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From the Journal of the Cincinnati Society of Natural History, Oct.
1892, Jan. 1893.


THE MYXOMYCETES OF THE MIAMI VALLEY, OHIO.

BY A. P. MORGAN.

First Paper.

(Read January 3, 1893.)


Table of Contents

MYXOMYCETES, Wallr.

  Order        Genera               Page
  LICEACEÆ.                            4
               Licea                   4
               Tubulina                6
               Lycogala                7
  RETICULARIACEÆ.                     10
               Reticularia            10
               Clathroptychium        12
               Cibraria               13
               Dictydium              16
  PERICHÆNACEÆ.                       19
               Perichæna              19
               Ophiotheca             21
  ARCYRIACEÆ.                         23
               Lachnobolus            23
               Arcyria                24
               Heterotrichia          27
  TRICHIACEÆ.                         28
               Hemiarcyria            29
               Calonema               33
               Trichia                34
               Oligonema              40
  STEMONITACEÆ.                       43
               Clastoderma            44
               Lamproderma            45
               Comatricha             48
               Stemonitis             52
               Enerthenema            56
               Diachaea               56
  DIDYMIACEÆ.                         58
               Didymium               59
               Spumaria               64
               Diderma                66
               Lepidoderma            72
  PHYSARACEÆ.                         73
               Angioridium            75
               Cienkowskia            75
               Leocarpus              76
               Physarella             78
               Cytidium               80
               Craterium              84
               Physarum               88
               Fuligo                102
               Badhamia              105
               Scyphium              109


  List or Illustrations

  Vol. XV.  Plate III.  Figs. 1-12.
  Vol. XVI. Plate I.    Figs. 13-24.
  Vol. XVI. Plate XI.   Figs. 25-36.
  Vol. XVI. Plate XII.  Figs. 37-48.
  Vol. XIX. Plate XIII. Figs. 49-55.
  Vol. XIX. Plate XIV.  Figs. 56-63.
  Vol. XIX. Plate XV.   Figs. 64-73.


PRESTON, HAMILTON COUNTY, OHIO, December 28, 1892.

MR. DAVIS L. JAMES

_Dear Sir_--Along with this I send you the first installment of the
papers, entitled "The Myxomycetes of the Miami Valley, Ohio."

The work in these papers is based upon my ample collection of
Myxomycetes growing in this region, comprising more than one hundred
species; these have been diligently compared with specimens obtained
from correspondents elsewhere in this country and in Europe.

At the same time, I have also included many extra limital species. This
has been done chiefly to more clearly elucidate the subject in places
where the local material is not sufficient.

The only apology I can make for the arrangement which I present, is that
I have been obliged to choose from several different systems. I have
aimed not to hamper myself, by attaching paramount importance to some
particular character throughout.

I purpose to furnish a synopsis of the whole at the end of the work.

  Very truly yours,
  A. P. MORGAN.

       *       *       *       *       *




MYXOMYCETES, Wallr.


Fructification essentially a minute membranaceous vesicle, the
SPORANGIUM inclosing the SPORES, the product of a motile protoplasmic
body called the PLASMODIUM.

Microscopic organisms with the habit of the Fungi. The ripe spore of the
Myxomycetes is globose or ellipsoidal in shape, with the epispore
colorless or colored, and smooth or marked by characteristic
surface--sculpture according to the species; the spore in germination
gives rise to an elongated protoplasmic body, which exhibits amoeboid
movements, and is known by the name of _swarm-cell_. The swarm-cells
multiply by bipartition, which may be repeated through several
generations; they then unite together to form the large motile
protoplasmic bodies named _plasmodia_. The newly-formed plasmodium is
distinguished by its greater size from the swarm-cells, while it
exhibits essentially the same movements and changes of shape. The
plasmodia gradually increase in size, and as they grow assume commonly
the form of branched strands; these spread over the surface of the
substratum, which is usually the decaying parts of plants, in the form
of veins and net-works of veins, giving rise to a copiously-branched
reticulated or frill-like expansion, which covers surfaces varying in
extent from a few to several centimeters. They are chiefly composed of a
soft protoplasm of the consistence of cream, which may be readily spread
out into a shapeless smear, and is usually colorless, but sometimes
exhibits brilliant colors of yellow, orange, rose, purple, etc. The
development of the plasmodium ceases with the formation of the _spores_
within their _sporangia_.

The formation of the sporangia out of the plasmodium appears under three
general forms, which, however, pass into each other and are, therefore,
not strictly limited.

_First:_ An entire plasmodium spread out on its substratum becomes
transformed into a sporangium, or it divides into a variable number of
unequal and irregular pieces, each of which undergoes transformation.
Such a sporangium lying flat on the substratum, more or less elongated
and flexuous, often branched and reticulate, is termed a
_plasmodiocarp_.

_Second:_ Erect sporangia on a narrow or stalk-like base, begin as
node-like swellings on the branches of the plasmodium, and gradually
rise to their ultimate form as the surrounding protoplasm flows into
them and assumes an upward direction. These sporangia are nearly always
perfectly regular in shape; they may be globose, obovoid, somewhat
depressed, or more or less elongated, and are either stipitate or
sessile.

_Third:_ A number of plasmodia collect together from every side and
become fused into a single body, often of considerable dimensions; from
these combinations originate the large spore-receptacles which are
called _æthalia_. The component sporangia may be regular in shape,
standing close together, in a single stratum, with entire connate walls;
more often, being elongated and flexuous, they branch and anastomose
freely, their walls becoming perforated and more or less defective; in
other cases, the æthalium is a compound plasmodiocarp, the narrow
sinuous sporangia branched and anastomosing in all directions, forming
an intricate network, closely packed together and inseparable. The
surface of the æthalium is often covered by a continuous layer of some
excreted substance, which is called the _common cortex_.

The wall of the sporangium, typically, is a thin, firm membrane,
colorless and pellucid, or colored in various shades of violet, brown,
yellow, etc.; it is sometimes extremely delicate, as in Lamproderma, or
is scarcely evident, as in Stemonitis; in other instances it is
thickened by deposits on the inner surface, as in Tubulina, or by
incrustations on the outer surface, as in Chondrioderma. The stipes are
tubes usually with a thick wall, which is often wrinkled and folded
lengthwise, and is confluent above with the wall of the sporangium; in
some cases the stipe also enters the sporangium, and is more or less
prolonged within it as a _columella_. The stipe commonly expands at the
base into a membrane, which fastens it to the substratum, and is called
the _hypothallus_; when all the stipes of the same group of sporangia
stand upon a single continuous membrane, it is called a _common
hypothallus_.

In the simplest forms, the cavity of the sporangium is filled
exclusively with the numerous spores; but in most all of the genera,
tubules or threads of different forms occur among the spores and
constitute the _capillitium_. The capillitium first makes its appearance
in Reticularia, in which upon the inner surface of the walls of the
sporangia there are abundant fibrous thickenings; next in Cribraria it
is spread over the inner surface of the wall, and is early separated
from it; here, also, it first assumes a more definite form and
arrangement; in Physarum it is in connection with the wall of the
sporangium only by its extremities while it traverses the interior with
a complicated network; in Stemonitis and its allies the capillitium
originates wholly from the columella; in most species of Arcyria it
issues from the interior of the stipe. The capillitium in Trichia
consists of numerous slender threads which are _free_, that is, are not
attached in any way; they are usually simple and pointed at each
extremity; the surface of these threads exhibits beautiful spiral
markings.




ORDER I. LICEACEÆ.


Sporangia always sessile, simple and regular or plasmodiocarp, sometimes
united into an æthalium. The wall a thin, firm, persistent membrane,
often granulose-thickened, usually rupturing irregularly. Spores
globose, usually some shade of umber or olivaceous, rarely violaceous.

The species of this order are the simplest of the Myxomycetes; the
sporangium, with a firm, persistent wall contains only the spores. There
is no trace of a capillitium, unless a few occasional threads in the
wall of Tubulina prefigure such a structure. To the genera of this order
is appended the anomalous genus Lycogala, which seems to me better
placed here than elsewhere.

TABLE OF GENERA OF LICEACEÆ.

1. LICEA. Sporangia simple and regular or plasmodiocarp, gregarious;
hypothallus none.

2. TUBULINA. Sporangia cylindric, or by mutual pressure becoming
prismatic, distinct or more or less connate and æthalioid, seated upon a
common hypothallus.

3. LYCOGALA. Æthalium with a firm membranaceous wall; from the inner
surface of the wall proceed numerous slender tubules, which are
intermingled with the spores.


I. LICEA, Schrad. Sporangia sessile, simple and regular or
plasmodiocarp, gregarious, close or scattered; hypothallus none; the
wall a thin, firm membrane, sometimes thickened with scales or granules,
breaking up irregularly and falling away or dehiscent in a regular
manner. Spores globose, variously colored.

The sporangia are not seated on a common hypothallus; they are,
consequently, more or less irregularly scattered about on the
substratum.

1. LICEA VARIABILIS, Schrad. Plasmodiocarp not much elongated, usually
scattered, sometimes closer and confluent, somewhat depressed, the
surface uneven or a little roughened and not shining, reddish-brown or
blackish in color; the wall a thin, firm pellucid membrane, covered by a
dense outer layer of thick brown or blackish scales, rupturing
irregularly. Spores in mass pale ochraceous, globose or oval, even or
nearly so, 13-16 mic. in diameter.

Growing on old wood. Plasmodiocarp 1-1.5 mm. in length, though sometimes
confluent and longer. The wall is thick and rough, not at all shining.
It is evidently the species of Schweinitz referred to by Fries under
this name.

2. LICEA LINDHEIMERI, Berk. Sporangia sessile, regular, globose,
gregarious, scattered or sometimes crowded, dark bay in color, smooth
and shining; the wall a thin membrane with a yellow-brown outer layer,
opaque, rupturing irregularly. Spores in mass bright bay, globose,
minutely warted, opaque, 5-6 mic. in diameter.

Growing on herbaceous stems sent from Texas. Sporangia about .4 mm. in
diameter. The bright bay mass of spores within will serve to distinguish
the species. The thin brown wall appears dark bay with the inclosed
spores.

3. LICEA BIFORIS, Morgan, n. sp. Sporangia regular, compressed, sessile
on a narrow base, gregarious; the wall thin, firm, smooth, yellow-brown
in color and nearly opaque, with minute scattered granules on the inner
surface, at maturity opening along the upper edge into two equal parts,
which remain persistent by the base. Spores yellow-brown in mass,
globose or oval, even, 9-12 mic. in diameter. See Plate III, Fig. 1.

Growing on the inside bark of Liriodendron. Sporangia .25-.40 mm. in
length, shaped exactly like a bivalve shell and opening in a similar
manner. I have also received specimens of this curious species from
Prof. J. Dearness, London, Canada.

4. LICEA PUSILLA, Schrad. Sporangia regular, sessile, hemispheric, the
base depressed, gregarious, chestnut-brown, shining; the wall thin,
smooth, dark-colored and nearly opaque, dehiscent at the apex into
regular segments. Spores in the mass blackish-brown, globose, even,
16-18 mic. in diameter.

Growing on old wood, Sporangium about 1 mm. in diameter. On account of
the color of the spores the genus _Protoderma_ was created for this
species by Rostafinski. It is number 2,316 of Schweinitz's N. A. Fungi.


II. TUBULINA, Pers. Sporangia cylindric, or by mutual pressure becoming
prismatic, distinct or more or less connate and æthalioid, the apex
convex, seated upon a common hypothallus; the wall a thin membrane,
minutely granulose, firm and quite persistent, gradually breaking away
from the apex downward. Spores abundant, globose, umber or olivaceous.

The sporangia usually stand erect in a single stratum, with their walls
separate or grown together: in the more compact æthalioid forms,
however, the sporangia, becoming elongated and flexuous, pass upward and
outward in various directions, branching and anastomosing freely. See
Plate III, Figs. 2, 3, 4.

1. TUBULINA CYLINDRICA, Bull. Sporangia cylindric, more or less
elongated, closely crowded, distinct or connate, pale umber to
rusty-brown in color, seated on a well developed hypothallus; the wall
thin, firm, with minute veins and granules, semi-opaque, pale umber,
often iridescent. Spores in mass pale umber to rusty-brown, globose,
most of the surface reticulate, 6-8 mic. in diameter.

Growing on old wood, mosses, etc. Æthalium circular or irregular in
shape, from one to several centimeters in extent, the individual
sporangia 2-4 mm. in height. Plasmodium at first milky-white, soon
changing to bright red, then to umber, becoming paler when mature and
dry.

2. TUBULINA CASPARYI, Rost. Sporangia more or less elongated, closely
crowded and prismatic, connate, pale umber to brown in color, seated on
a conspicuous hypothallus; the wall thin, firm, minutely granulose,
semi-opaque, pale umber, iridescent when well matured; all or many of
the sporangia traversed by a central columella, from which a few narrow
bands of the membrane stretch to the adjacent walls. Spores in the mass
pale umber to brown, globose, the surface reticulate, 7-9 mic. in
diameter.

Growing on old prostrate trunks. Æthalium two or three to several
centimeters in extent, the individual sporangia 3-5 mm. in height.
Plasmodium white, the immature sporangia dull-gray tinged with sienna
color. The columella, with its radiating bits of membrane, is the same
substance as the wall; it may be a reëntrant edge of the prismatic
sporangium, caused by excessive crowding together; at least, this may be
regarded as its origin; there may have arisen some further adaptation.
The species is _Siphoptychium Casparyi_, Rost. I am indebted to Dr.
George A. Rex for the specimens I have examined.

3. TUBULINA CÆSPITOSA, Peck. Sporangia short-cylindric, closely crowded,
distinct or connate, argillaceous olive to olive-brown in color, seated
on a well-developed hypothallus; the wall a thin membrane, with a dense
layer of minute dark-colored round granules on the inner surface. Spores
argillaceous olive in the mass, globose, minutely warted, 6-8 mic. in
diameter.

Growing on old wood. Æthalium in irregular patches sometimes several
centimeters in extent, the single sporangia about 1 mm. in height.
Plasmodium dark olivaceous, the sporangia blackish if dried when
immature, taking a paler shade of olivaceous, according to development
and maturity. This is _Perichæna cæspitosa_, Peck, in the 31st N. Y.
Report.


III. LYCOGALA, Mich. Æthalium with a firm membranaceous wall; from the
inner surface of the wall proceed numerous slender tubules, which are
intermingled with the spores. The material of the wall appears under
three different forms: the inner layer is a thin membrane, uniform in
structure, of a yellow-brown color, and semi-pellucid; the outer layer
consists of large flat roundish or irregular vesicles, brown in color,
filled with minute granules, and arranged in one or more strata; from
these vesicles originate the tubules, which traverse the wall for a
certain distance, and then enter the interior among the spores; the
tubules are more or less compressed, simple or branched, and the surface
is ornamented with warts and ridges, which sometimes form irregular
rings and reticulations.

If the sporophores in this genus be regarded as simple sporangia, which
is the view that Rostafinski takes of one of the species, the tubules
are simply the peculiar threads of a capillitium. If, however, the
æthalium is a compound plasmodiocarp, the tubules stand for the original
plasmodial strands and, consequently, represent the component sporangia.

1. LYCOGALA CONICUM, Pers. Æthalia small, ovoid-conic, gregarious,
sometimes close together with the bases confluent, the surface pale
umber or olivaceous marked with short brown lines, regularly dehiscent
at the apex. The wall thin; the outer layer not continuous, the
irregular brown vesicles disposed in angular patches and elongated
bands, which have a somewhat reticulate arrangement. The tubules appear
as a thin stratum upon the inner membrane; they do not branch, and they
send long slender simple extremities inward among the spores. Spores in
mass pale ochraceous, globose, minutely warted, 5-6 mic. in diameter.
See Plate III, Fig. 5.

Growing on old wood. Æthalium 2-5 mm. in height, the tubules 3-8 mic. in
thickness. This is _Dermodium conicum_ of Rostafinski's monograph, but
the structure is essentially the same as in the other species. Massee
evidently did not have specimens of this species. I have never seen any
branching of the tubules either in the wall or in the free extremities
of the interior.

2. LYCOGALA EXIGUUM, Morg. n. sp. Æthalia small, globose, gregarious,
the surface dark brown or blackish, minutely scaly, irregularly
dehiscent. The wall thin; the vesicles with a dark polygonal outline,
disposed in thin irregular reticulate patches, which are more or less
confluent. The tubules appear as an interwoven fibrous stratum upon the
inner membrane; they send long slender branched extremities inward among
the spores. Spores in mass pale ochraceous, globose, nearly smooth, 5-6
mic. in diameter. See Plate III, Fig. 6.

Growing on old wood. Æthalium 2-5 mm. in diameter, the threads 2-10 mic.
in thickness, with very slight thickenings of the membrane. The
polygonal vesicles give a reticulate appearance to the dark-brown
patches which ornament the surface of the wall.

3. LYCOGALA EPIDENDRUM, Buxb. Æthalia subglobose, gregarious, sometimes
closely crowded and irregular, the surface umber, brown or olivaceous,
minutely warted, at length, irregularly dehiscent at or about the apex.
The wall thick, the brown vesicles loosely aggregated and densely
agglutinated together, traversed in all directions by the much-branched
tubules, which send long-branched extremities inward among the spores;
the main branches thick and flat, with wide expansions, especially at
the angles, the ultimate branchlets more slender and obtuse at the apex.
Spores in the mass from pale to reddish ochre, globose, minutely warted,
5-6 mic. in diameter. See Plate III, Fig. 7.

Growing on old wood. Æthalium 5-12 mm. in diameter, the width of the
tubules varying from 12-25 mic. in the main branches, with broader
expansions at the angles, to 6-12 mic. in the more slender final
branchlets. This is one of the most common of the Myxomycetes; it grows
in all countries, and in this region may be found on old trunks at all
seasons of the year.

4. LYCOGALA FLAVOFUSCUM, Ehr. Æthalia large, subglobose or somewhat
pulvinate, solitary or gregarious, the surface at first silvery-shining,
becoming yellow-brown, minutely areolate, irregularly dehiscent. The
wall very thick and firm, hard and rigid; the thick outer layer of
roundish brown vesicles closely compacted in numerous strata; from the
vesicles of the lower strata the long and broad much-branched tubules
proceed into the interior among the spores; the ultimate branchlets
clavate and obtuse at the apex. Spores in the mass pale ochre, cinerous
or brownish, globose, minutely warted, 5-6 mic. in diameter. See Plate
III, Figs. 8, 9.

Growing on old trunks. Æthalium 1 to several centimeters in diameter,
the width of the tubules varying from 25-60 mic. in the main branches,
with sometimes much broader expansions at the angles, to 10-25 mic. in
the ultimate branchlets. The brown vesicles of the outer wall are easily
separated from each other and emptied of their contents by maceration;
it is then seen that a thin pellucid membrane incloses numerous roundish
granules, much resembling the spores, but usually a little larger, 5-8
mic. in diameter.




ORDER II.--RETICULARIACEÆ.


Sporangia simple, regular and stipitate, or compound, forming an
æthalium; the wall a thin membrane with distinct fibrous thickenings
upon the inner surface, the membrane, or at least certain portions of
it, disappearing usually at the maturity of the spores, leaving behind
the more permanent fibrous thickenings as a more or less definite
capillitium. Spores globose, purple, brown, ochraceous, rarely
violaceous.

In this order the threads of a capillitium first make their appearance;
but they are confined to the inner surface of the wall of the
sporangium, being set at liberty by the early decay of the outer
membrane.

TABLE OF GENERA OF RETICULARIACEÆ.

_a. Æthalia._

1. RETICULARIA. Æthalium composed of numerous slender sinuous sporangia
which repeatedly branch and anastomose.

2. CLATHROPTYCHIUM. Æthalium composed of numerous regular erect
sporangia.

_b. Sporangia simple._

3. CRIBRARIA. Capillitium of slender threads combined into a network of
polygonal meshes.

4. DICTYDIUM. Capillitium of numerous convergent ribs, which extend from
base to apex, and are united by fine transverse fibers, thus forming a
network of rectangular meshes.


I. RETICULARIA, Bull. Æthalium composed of numerous slender sinuous
sporangia, which repeatedly branch and anastomose, closely packed
together and seated upon a common hypothallus, the apices of the final
branches coherent at the surface, and naked or covered by an additional
corticate layer. Walls of the sporangia consisting of a thin membrane,
with abundant fibrous thickenings, presenting broad expansions,
narrowing to thin flat bands, and reduced in many places to slender
fibrous threads. Spores abundant, globose, umber or violaceous.

After the maturity of the spores disintegration of the sporangial wall
begins, the thin membrane disappearing more rapidly than the fibrous
thickenings or the portions of the sporangial walls near the base, which
are more compactly grown together; there is thus left at each stage an
increasing number of the shreddy fibers mingled with the spores.

1. RETICULARIA SPLENDENS, Morg. n. sp. Æthalium pulvinate, circular or
more or less elongated and irregular, seated on a conspicuous silvery
hypothallus; the surface naked, bright umber, smooth and shining. Walls
of the sporangia firm and quite persistent, pale umber, slowly
disintegrating, consisting for the most part of wide expansions, with
their angles tapering to narrow bands and slender threads. Spores in the
mass pale umber, globose, most of the surface reticulate, 7-9 mic. in
diameter. See Plate III, Fig. 10.

Growing on old wood. Æthalium from 1 to several centimeters in extent
and 5-10 mm. in thickness, usually growing singly, rarely close enough
to be confluent. This species has lately been referred to _Reticularia
rozeana_, Rost., but it varies greatly from the account given of that
species in the Journal of Botany for September, 1891.

2. RETICULARIA UMBRINA, Fr. Æthalium pulvinate, roundish, more or less
irregular, the surface covered by a thin, silvery, shining, common
cortex, which at the base is confluent with the hypothallus. Walls of
the sporangia umber or rusty-brown next the base, with broad expansions
in places thickly grown together, toward the surface passing into narrow
bands and abundant fibrous threads, which rapidly disintegrate. Spores
in the mass umber or rusty brown, globose, most of the surface
reticulate, 7-9 mic. in diameter.

Growing on old trunks. Æthalium one to several centimeters in extent,
and 5-15 mm. in thickness. The walls of the sporangia are much more
reduced to the shreddy fibrous condition than in the preceding species,
and on this account they much more rapidly disintegrate, causing the
æthalium soon to collapse. It is _Reticularia Lycoperdon_, Bull.

3. RETICULARIA ATRA, A. & S. Æthalium pulvinate, variable in form and
size, covered with a thin, fragile, blackish, cortical layer. Walls of
the sporangia violaceous, next the base with broad expansions, in places
more thickly grown together, toward the surface becoming narrow with
more abundant fibrous threads, sometimes presenting a loose irregular
network, the whole structure, however, quite variable, according to the
stage of the disintegration. Spores globose, violet, minutely warted,
14-16 mic. in diameter.

Growing on wood and bark, especially of pine. Æthalium 2 or 3 to several
centimeters in extent. This is _Amaurochæte atra_ of Rostafinski's
monograph, but the structure appears to be altogether similar to that of
_Reticularia umbrina_.


II. CLATHROPTYCHIUM, Rost. Æthalium composed of numerous regular erect
sporangia, seated in a single compact stratum, on a well-developed
hypothallus, the surface formed by the coherent apices. Sporangia at
first cylindric, with the apex convex and the wall entire; soon, by
mutual pressure, they become prismatic and the lateral faces disappear,
leaving the edges and the apex permanent. Spores globose, ochraceous.

1. CLATHROPTYCHIUM RUGULOSUM, Wallr. Æthalium composed of numerous very
slender sporangia, closely compacted into a single stratum, and seated
on a conspicuous silvery hypothallus; the surface ochroleucous, honey
color or olivaceous. The sporangia are typically hexangular when the
lateral faces disappear, leaving at the edges six simple triangular
threads, extending from the angles of the hexagonal apex downward to the
base. Spores in the mass ochraceous, yellowish or brownish, globose,
minutely warted, 8-10 mic. in diameter.

Growing on old wood. Æthalium somewhat circular, or often quite
irregular in shape, 1 to several centimeters in extent, the individual
sporangia nearly 1 mm. in height, but scarcely .1 mm. in thickness.
Deviations from the typical form of the sporangia sometimes occur, they
are not seldom pentangular, and I have seen the apices quadrangular,
with only four threads, or even triangular, and with but three; the
threads, too, are said occasionally to branch and anastomose.
_Reticularia plumbea_, Fries, S. M. III, 88; and _Ostracoderma
spadiceum_, Schw., N. A. Fungi No. 2,381.


III. CRIBRARIA, Pers. Sporangia simple, globose or obovoid, stipitate,
often cernuous; the wall regularly thickened on the inner surface in two
ways, the lower basal portion by radiating ribs consisting of minute
brown granules, the upper part by slender threads combined into a
network of polygonal meshes; the basal portion of the membrane is
commonly persistent with its thickening and is called the _calyculus_,
the upper part nearly always disappears from the network at maturity;
there are usually nodules of the brown granules at the angles of the
network. Spores globose, purple, brown, ochraceous.

_a. Sporangium, large._

1. CRIBRARIA ARGILLACEA, Pers. Sporangia globose or obovoid, stipitate
or nearly sessile, standing close together on a thin and evanescent
hypothallus; the wall quite firm, silvery-shining, the greater portion
persistent, breaking away about the apex; calyculus small, the brown
radiating ribs soon passing into a network of polygonal meshes, the
threads with irregular granulose-thickened portions at intervals
throughout their whole extent. Stipe very short, erect, brown. Spores in
the mass argillaceous, globose, 5-7 mic. in diameter.

Growing in large irregular patches on rotten trunks. Sporangia .6-.8 mm.
in diameter, the stipe always much shorter than the sporangium,
sometimes nearly obsolete. The resemblance of this species to some forms
of _Tubulina cæspitosa_ is very great.

2. CRIBRARIA VULGARIS, Schrad. Sporangium large, globose, stipitate,
somewhat cernuous; the calyculus brown, finely ribbed and granulose
within, occupying but a small part of the sporangium; the network of
slender threads, with very small nodules at the angles, each with
several (3-7) radiating threads, sometimes with one or two free
extremities, the meshes triangular or rhombic. Stipe rather short,
stout, tapering upward, usually a little bent or curved at the apex,
dark purplish brown in color. Spores in the mass pale ochraceous,
globose, even, 5-7 mic. in diameter.

Growing on old wood. Sporangium .5-.7 mm. in diameter, the stipe two or
three times the diameter of the sporangium in length. Recognized by the
large sporangium and the very small nodules with their few radiating
threads.

3. CRIBRARIA DICTYDIOIDES, C. & B. Sporangium large, globose, stipitate,
cernuous; the calyculus small, with thickish brown ribs, from which the
outer thin membrane often disappears soon after maturity; the network of
slender threads, with large brown nodules at the angles, more or less
elongated and irregular in shape, each with numerous (5-15) radiating
threads, usually some with free extremities, the meshes largely
triangular. Stipe long, tapering upward, flexuous, curved at the apex,
dark purplish-brown in color. Spores in mass pale ochraceous, globose,
even, 5-7 mic. in diameter.

Growing on rotten wood, especially of oak. Sporangium .5-.6 mm. in
diameter, the stipe from three to five times as long. This species
appears to be intermediate between _Cribraria vulgaris_ and _Cribraria
intricata_; the nodules are usually large and irregular, but the
characteristic parallel threads of _C. intricata_ do not often occur.
The outer membrane of the calyculus is by no means always absent.

4. CRIBRARIA ELEGANS, B. & C. Sporangium rather large, globose,
stipitate, somewhat cernuous; the calyculus thickly coated inside with
dark purple granules, faintly ribbed, occupying about a third part of
the sporangium; the network of slender threads, with large irregular
dark purple nodules, quite variable in shape and size, angular and
lobed, below sometimes much elongated, the meshes very irregular. Stipe
rather short, tapering upward, bent at the apex, dark purple in color.
Spores in the mass bright purple, globose, even, 5-7 mic. in diameter.

Growing on old wood. Sporangium .4-.5 mm. in diameter, the stipe two or
three times as long. It does not appear to be greatly different from
_Cribraria purpurea_, Schrad.

_b. Sporangium, small._

5. CRIBRARIA TENELLA, Schrad. Sporangium small, globose, stipitate,
cernuous; the calyculus brown, shining, granulose within and faintly
ribbed, occupying from one-fourth to one-half the sporangium, sometimes
the outer thin membrane early disappearing; the network of slender
threads with small roundish or irregular nodules at the angles, each
with several (4-8) radiating threads, sometimes two or three with free
extremities, the meshes triangular or rhombic. Stipe long, tapering
upward, flexuous, curved at the apex, purplish-brown in color. Spores
pale ochraceous in mass, globose, even, 5-7 mic. in diameter.

Growing on old wood. The sporangium .3-.4 mm. in diameter, the stipe
three to five times as long. This is a much more delicate species than
_Cribraria dictydioides_. The calyculus is variable in size; in some
examples the thin connecting membrane between the ribs has disappeared.

6. CRIBRARIA MICROCARPA, Schrad. Sporangium very small, globose,
stipitate, somewhat cernuous; the calyculus represented by a few short
brown ribs, the outer membrane soon disappearing; the network of slender
threads, with small roundish nodules at the angles, each with several
(4-6) radiating threads, with an occasional free extremity, the meshes
largely rhombic. Stipe very long, slender, somewhat flexuous, bent at
the apex, purplish-brown in color. Spores in mass pale ochraceous,
globose, even, 6-7 mic. in diameter.

Growing on old wood. Sporangium .22-.27 mm. in diameter, the stipes 1-2
mm. in length. Readily distinguished by its very small sporangium and
the comparatively very long stem. I am indebted to Dr. George A. Rex for
specimens of this species.

7. CRIBRARIA CUPREA, Morg. n. sp. Sporangium very small, oval or
somewhat obovoid, stipitate, cernuous; the calyculus copper-colored,
finely ribbed and granulose within, occupying from one-third to one-half
the sporangium; the network of slender threads, with rather large
triangular or quadrilateral meshes, and with large irregular dark
copper-colored nodules, each having several (4-7) radiating threads,
with an occasional free extremity. Stipe not very long, tapering upward,
curved at the apex, of the same color as the sporangium or darker below.
Spores pale coppery in mass, globose, even, 6-7 mic. in diameter. See
Plate III, Fig. 11.

Growing on old wood. Sporangium .30-.35 X .25-.30 mm, the stipe two to
four times as long as the sporangium. A minute species, easily
recognized by its almost uniform color of bright new copper.


IV. DICTYDIUM, Schrad. Sporangium simple, depressed-globose, stipitate,
cernuous; the wall regularly thickened on the inner surface by numerous
convergent ribs, which extend from base to apex and are united by fine
transverse fibers, thus forming a network of rectangular meshes; the
basal portion of the membrane sometimes persists as a calyculus, the
upper part disappears at maturity. Spores globose; purplish.

The ribs run from base to apex like the meridians on a globe; they are
simple, or here and there they separate into two divergent branches,
which sometimes again converge into one; at the apex of the sporangium
there is usually a small irregular net in which all the ribs terminate.

1. DICTYDIUM CERNUUM, Pers. Sporangium depressed-globose, umbilicate at
the apex, stipitate, cernuous, purplish-brown in color; the calyculus
granulose within, occupying from one-fourth to one-third of the
sporangium, the ribs united by firm, persistent fibers. Stipe not very
long, erect, tapering upward, bent at the apex, purplish-brown, the apex
pale and pellucid, standing on a small hypothallus. Spores
purplish-brown in mass, globose, even, 5-7 mic. in diameter.

Growing on old wood. Sporangium .4-.5 mm. in diameter, the stipe two or
three times longer than the diameter of the sporangium. This appears to
be the species figured and described by Rostafinski and by Massee.

2. DICTYDIUM LONGIPES, Morg. n. sp. Sporangium large, depressed-globose,
the apex umbilicate, stipitate, cernuous, dark purple in color;
calyculus usually wholly wanting, the ribs united by weak fibers, which
are easily torn asunder, allowing the ribs to curl up inwards. Stipe
very long, flexuous, tapering upward, curved and twisted at the apex,
dark purple in color, standing on a thin hypothallus. Spores in the mass
dark purple, globose, even, 5-7 mic. in diameter. See Plate III, Fig.
12.

Growing on rotten wood, mosses, etc. Sporangium .5-.7 mm. in diameter,
the stipe three to five times as long. This is a much larger species
than the preceding; it has a uniform dark purple hue, the stipe is very
long and much bent and twisted, the ribs of the sporangium are soon torn
apart and rolled inward.


EXPLANATION OF PLATE III

Fig. 1.--Licea biforis, Morgan, n. sp.

Figs. 2, 3, 4.--Diagrammatic representation of the structure of Tubulina

Fig. 5.--Lycogala conicum, Pers., natural size

Fig. 6.--Lycogala exiguum, Morgan, n. sp., natural size

Fig. 7.--Lycogala epidendrum, Buxb., natural size

Fig. 8.--Lycogala flavofuscum, Ehr., natural size

Fig. 9.--Portion of tubule of Lycogala flavofuscum

Fig. 10.--Reticularia splendens, Morgan, n. sp., natural size

Fig. 11.--Cribraria cuprea, Morgan, n. sp.

Fig. 12.--Dictydium longipes, Morgan, n. sp.

[Illustration: The Journal of the Cin. Soc. Natural History.

  VOL. XV.                                      PLATE III.]

       *       *       *       *       *

From the Journal of the Cincinnati Society of Natural History, April,
1893.


THE MYXOMYCETES OF THE MIAMI VALLEY, OHIO.

BY A. P. MORGAN.

Second Paper.

(Read May 2, 1893.)




ORDER III. PERICHÆNACEÆ.


Sporangia sessile or plasmodiocarp; the wall a thin membrane, with a
more or less thickened outer layer of minute brownish scales and
granules. Capillitium of long and very slender tubules, proceeding from
numerous points of the sporangial wall, loosely branched, forming no
evident network, the surface minutely warted or spinulose. Spores
globose, oval, or somewhat irregular, yellow.

The order is distinguished by the sessile sporangia, with thick brown
walls, and the very slender threads of the capillitium, with irregular
and indefinite markings.

TABLE OF GENERA OF PERICHÆNACEÆ.

1. PERICHÆNA. Sporangia more or less depressed, roundish or more
commonly polygonal and irregular, dehiscent in a circumscissile manner.

2. OPHIOTHECA. Plasmodiocarp terete and more or less elongated, bent and
flexuous, sometimes annular or reticulate, irregularly dehiscent.


I. PERICHÆNA, Fr. Sporangia more or less depressed, roundish or more
commonly polygonal and irregular, the edges approximate and sometimes
confluent; the wall a thin membrane, with a thick dense yellow-brown
outer layer of minute scales and granules, becoming darker at the
surface, dehiscent in a circumscissile manner. Capillitium of very
slender loosely-branched threads, with the surface minutely warted.
Spores globose, oval or somewhat irregular, yellow.

Distinguished from Ophiotheca by the flattened sporangium with a regular
circumscissile dehiscence.

1. PERICHÆNA DEPRESSA, Lib. Sporangia very much depressed, polygonal,
irregular, crowded, the edges contiguous, sometimes confluent; the wall
thick, yellow-brown within and scarcely impressed by the spores; the
outer surface smooth, brown-red to brown or blackish in color, dehiscent
in a circumscissile manner. Capillitium of slender loosely-branched
threads, 1-3 mic. in thickness, the surface merely uneven or very
minutely warted. Spores globose, yellow, 9-10 mic. in diameter. See
Plate I, Fig. 13.

Growing on the inside of the bark of Juglans, Acer, etc. Sporangia
variable in size, 7-1.3 mm. in breadth, irregular and angular, much
flattened. It is said to include _Perichæna vaporaria_, Schw.

2. PERICHÆNA IRREGULARIS, B. & C. Sporangia depressed, irregular,
polygonal, crowded, the edges contiguous and sometimes confluent; the
wall thick, yellow inside and faintly reticulately impressed by the
spores, the outer surface smooth, purplish-brown, dehiscent in a
circumscissile manner. Capillitium of slender-loosely branched threads,
about 2 mic. in thickness, the surface minutely warted or spinulose.
Spores subglobose, yellow, 9-10 mic. in diameter.

Growing on the outer bark of Acer, etc. Sporangium .5-.6 mm. in width,
closely crowded and irregular. It is much smaller than _Perichæna
depressa_, and its threads are more distinctly warted and spinulose.

3. PERICHÆNA CORTICALIS, Batsch. Sporangia globose, the base depressed,
gregarious: the wall thick, yellow within and distinctly reticulately
impressed by the spores, the outer surface reddish-brown or yellow-brown
in color, dehiscent in a circumscissile manner. Capillitium of slender
loosely-branched threads, about 2 mic. in thickness, the surface very
minutely warted. Spores subglobose, yellow, 10-12 mic. in diameter.

Growing on the inside of the bark of Elm. Sporangia .5-.6 mm. in
diameter, quite regular in shape, with a slightly flattened base. My
specimens are from Prof. McBride, of Iowa.

4. PERICHÆNA MARGINATA, Schw. Sporangia depressed, polygonal,
approximate and sometimes confluent, the surface cinereous-pulverulent,
seated on a silvery hypothallus; the wall firm, thick, the outer surface
yellow-brown, covered with minute whitish scales, the inner surface
yellow, deeply reticulately impressed by the spores which rest against
it, dehiscent in a circumscissile manner. Capillitium consisting of a
few simple or somewhat branched threads or well-nigh obsolete. Spores
subglobose, yellow, 12-14 mic. in diameter.

Growing on the outer surface of the bark of Acer, Fagus, etc. Sporangia
.4-.6 mm. in width. This is plainly _Perichæna cano-flavescens_,
Raunkier. I do not find any threads of a capillitium in my specimens.


II. OPHIOTHECA, Currey. Plasmodiocarp terete and more or less elongated,
bent and flexuous, sometimes annular or reticulate, the surface not
polished or shining: the wall a thin membrane, with a thin outer layer
of minute scales and granules, irregularly dehiscent. Capillitium of
very slender loosely-branched threads, with the surface minutely warted
and spinulose. Spores globose, oval or somewhat irregular, yellow.

Distinguished from Perichæna by the terete plasmodiocarp and by the more
spinulose capillitium. _Cornuvia_ of Rostafinski.

1. OPHIOTHECA CHRYSOSPERMA, Currey. Plasmodiocarp globose or oblong to
elongated, and bent or flexuous, sometimes annular or branched and
reticulate, dull brown in color; the wall a thin yellowish membrane,
with a thin yellow-brown outer layer, irregularly dehiscent. Capillitium
of slender loosely-branched threads, 2-3 mic. in thickness, the surface
minutely spinulose. Spores subglobose, yellow, 8-9 mic. in diameter.

Growing on the inner surface of old bark of Quercus, etc. Plasmodiocarp
.4-.5 mm. in thickness, variable in length. _Cornuvia circumscissa_ of
Rostafinski's monograph.

2. OPHIOTHECA WRIGHTII, B. & C. Plasmodiocarp more or less elongated,
bent and flexuous, very commonly in small rings, from brownish-ochre to
brown or blackish in color, not polished; the wall a thin yellow
membrane, with a thin brown outer layer, irregularly dehiscent.
Capillitium of slender loosely-branched threads, 2-3 mic. in thickness,
furnished with numerous straight or bent long-pointed spinules. Spores
subglobose, yellow, minutely warted, 10-12 mic. in diameter. See Plate
I, Fig. 14.

Growing on the inside of bark of Acer, Carya, etc. Plasmodiocarp about
.5 mm. in thickness, variable in length, often in small rings 1-2 mm. in
diameter. The prickly threads are quite characteristic; the spinules are
3-5 mic. in length. _Hemiarcyria melanopeziza_, Speg., is evidently the
same thing.

3. OPHIOTHECA VERMICULARIS, Schw. Plasmodiocarp terete and more or less
elongated, bent and flexuous, sometimes annular or reticulate, the
surface not polished, brownish in color; the wall a thin yellow
membrane, covered on the outside by a more or less thickened brown layer
of scales and granules, irregularly dehiscent. Capillitium of slender
loosely branched threads, 2-3 mic. in thickness, the surface with minute
warts and ridges. Spores subglobose, yellow, 10-12 mic. in diameter.

Growing on the inside of old bark. Plasmodiocarp about .4 mm. in
thickness and various in length; in my specimens the sporangia are
mostly small rings. The species looks exactly like _Ophiotheca
Wrightii_, but the character of the threads is quite different.

4. OPHIOTHECA PALLIDA, B. & C. Plasmodiocarp terete, oblong or elongated
annular and flexuous, the surface dull, pale ochraceous; the wall a thin
pellucid membrane, minutely granulate, with a thin pale ochraceous outer
layer, irregularly dehiscent. Capillitium of slender loosely-branched
threads, 2-3 mic. in thickness, the surface minutely warted or
spinulose. Spores subglobose, pale yellow, 10-12 mic. in diameter.

Growing on dead stems of herbaceous plants. Plasmodiocarp .3-.4 mm. in
thickness, variable in length, sometimes short and roundish or oblong,
sometimes much elongated and flexuous. More delicate than _Ophiotheca
vermicularis_, and distinguished by its pallid color throughout.




ORDER IV. ARCYRIACEÆ.


Sporangia regular and stipitate, rarely sessile; the wall a thin
membrane, minutely granulose, colored as the spores and capillitium, the
upper part soon torn away in a somewhat circumscissile manner, and early
disappearing. Capillitium of slender tubules, repeatedly branching and
anastomosing to form a complicated network of evident meshes, more or
less expanded after dehiscence; the surface of the threads minutely
warted or spinulose or with elevated ridges in the shape of rings, half
rings or reticulations.

This order is specially distinguished by the threads of the capillitium
forming a complicated network of evident meshes.

TABLE OF GENERA OF ARCYRIACEÆ.

1. LACHNOBOLUS. Capillitium of slender tubules, quite variable in
thickness, proceeding from numerous points of the sporangial wall.

2. ARCYRIA. Capillitium of slender tubules, issuing from the interior of
the stipe, the network without any free extremities.

3. HETEROTRICHIA. Capillitium issuing from the interior of the stipe,
the peripheral portion of the network bearing numerous short acute free
branches.


I. LACHNOBOLUS, Fr. Sporangia stipitate or sessile, the wall a thin
delicate membrane, minutely granulose, rupturing irregularly. Stipe
short or sometimes wanting. Capillitium of slender tubules quite
variable in thickness, proceeding from numerous points of the sporangial
wall and forming a complicated network, the surface minutely warted or
spinulose. Spores globose, yellowish or flesh-color.

This genus differs from Arcyria in the capillitium springing from
numerous points of the sporangial wall.

1. LACHNOBOLUS GLOBOSUS, Schw. Sporangia globose, stipitate, pale
yellow, changing to clay-color; the wall thin and delicate, pellucid,
minutely granulose, the upper part torn away and soon disappearing, the
lower half more persistent. Stipe short, tapering upward, expanding at
the base into a small hypothallus. Capillitium arising from the lower
portion of the sporangium, forming a complicated network, the threads
3-5 mic. in thickness, the surface closely covered with minute warts.
Spores globose, pale yellow to clay-color in mass, 8-9 mic. in diameter.
See Plate I, Fig. 15.

Growing on the spines of Chestnut burs. Sporangia .5-.6 mm. in diameter,
the stipe shorter than the sporangium.

2. LACHNOBOLUS INCARNATUS, A. & S. Sporangia globose or ellipsoidal,
substipitate, closely crowded and seated on a common hypothallus; the
wall thin and delicate, pellucid, minutely granulose, dehiscing
irregularly. Stipe very short or often obsolete. Capillitium proceeding
from the inner surface of the sporangial wall, forming a complicated
network, the threads extremely variable in thickness, minutely warted
and spinulose. Spores globose, flesh-color in the mass, 8-9 mic. in
diameter.

Growing on old wood. Sporangia .5-.8 mm. in height, sessile on a narrow
base or with a very short stipe; the threads of the capillitium are
generally 3-5 mic. in thickness, but there are broader expansions at the
nodes and elsewhere. My specimens are from Prof. McBride, of Iowa. The
species is extremely variable, and these specimens differ much from
those described elsewhere.


II. ARCYRIA, Hill. Sporangia regular ovoid to cylindric, stipitate; the
wall a thin delicate membrane, circumscissile or torn away near the
base, the upper portion evanescent, the lower part persistent, small and
cup-shaped. Stipe more or less elongated, the interior containing
roundish vesicles which become smaller upward, and gradually pass into
the normal spores. Capillitium of slender tubules, issuing from the
interior of the stipe, forming a complicated network, without any free
extremities, the surface minutely warted or spinulose or with annular
ridges. Spores globose, red, brown, yellow, cinereous.

§1. CLATHROIDES, Mich. Capillitium closely attached by a few threads
which issue from the interior of the stipe, and are free from the
calyculus (except in _A. punicea_), much elongated after dehiscence,
weak and drooping or prostrate; the meshes open and irregular, not
differing externally and internally, their threads similar throughout,
the warts or ridges of the surface exhibiting a spiral arrangement.

1. ARCYRIA PUNICEA, Pers. Sporangium ovoid, more or less elongated; the
calyculus small, plicate-sulcate. Stipe long, erect, brownish-red in
color, expanded at the base into a small hypothallus. Capillitium firmly
attached by numerous threads which are connate with the wall of the
calyculus, much elongated after dehiscence, ovoid-oblong to cylindric,
bright red in color, fading to red-brown or brownish-ochre; the threads
uniform in thickness, about 3 mic., the surface with a series of
prominent half-rings, which wind around the thread in a long spiral.
Spores globose, even, 6-8 mic. in diameter.

Growing on old bark, wood, mosses, etc. The stipe 1-2 mm. in length, the
capillitium elongated 2-4 mm. The commonest of the species, conspicuous
by reason of its bright red color.

2. ARCYRIA MINOR, Schw. Sporangium ovoid-oblong; the calyculus small,
sulcate and ribbed, granulose. Stipe short, erect, brownish-red in
color, standing on a thin hypothallus. Capillitium much elongated after
dehiscence, oblong to cylindric, lax and prostrate, bright red to
brownish in color; the threads uniform in thickness, 2.5-3 mic., the
surface with a series of prominent half-rings, which wind around the
thread in a long spiral. Spores globose, even, 7-9 mic. in diameter. See
Plate I, Fig. 17.

Growing on old wood, bark, Polyporus, etc. The stipe .4-.7 mm. in
length, the capillitium elongated 1.5-3 mm. Not uncommon, but it is
usually referred to _A. adnata_.

3. ARCYRIA ADNATA, Batsch. Sporangium ovoid; the calyculus very small,
finely ribbed and granulose. Stipe very short or entirely wanting.
Capillitium much expanded after dehiscence, globose or obovoid, pale red
to brownish in color; the threads uniform in thickness, about 4 mic.,
the surface with a series of prominent half-rings with mingled warts and
spines, which wind around the thread in a long spiral. Spores globose,
even, 6-8 mic. in diameter.

Growing in small clusters on old wood. A small species, the capillitium
expanded 1-2 mm., the stipe extremely short, or altogether absent.

4. ARCYRIA NUTANS, Bull. Sporangium cylindric; the calyculus small,
granulose, ribbed and sulcate. Stipe very short, arising from a common
hypothallus. Capillitium greatly elongated after dehiscence, cylindric,
drooping and pendulous, pale yellow or pale ochraceous; the threads 3-4
mic. in thickness, the surface covered with spinules, among which are
rings and half-rings, with an indistinct spiral arrangement. Spores
globose, even, 7-9 mic. in diameter.

Growing on old wood. The capillitium elongated 4-8 mm., the stipe very
short. A very conspicuous species by reason of its long pale yellow
capillitium.

§2. PLECTANELLA. Capillitium erect, firmly attached by numerous threads,
which issue from the interior of the stipe, but are connate with the
wall of the calyculus, after dehiscence not much expanded: the meshes at
the surface of the network much smaller than those within, folded back
and forth, narrow and irregular, their threads densely warted or
spinulose; the meshes of the interior much larger, open and expanded,
their threads with minute scattered warts or perfectly smooth.

5. ARCYRIA CINEREA, Bull. Sporangium ovoid or oblong-ovoid; the
calyculus very small. Stipe long, erect, cinereous, becoming blackish,
standing on a thin hypothallus. Capillitium not much expanded after
dehiscence, ovoid-oblong, erect, pale cinereous, sometimes pale
yellowish; the external threads densely spinulose, 2-3 mic. in
thickness; the threads of the interior thicker, 3-5 mic., and very
minutely warted or quite smooth. Spores globose, even, 6-8 mic. in
diameter.

Growing on old wood. Capillitium 1-2 mm. long, the stipe about the same
length.

6. ARCYRIA COOKEI, Mass. Sporangium ovoid-cylindric, the calyculus very
small. Stipe long, erect, gray to mouse-color, darker below, arising
from a thin hypothallus. Capillitium not much expanded after dehiscence,
ovoid-cylindric, erect, gray to mouse-color; the superficial threads
densely and uniformly covered with minute warts, 3-5 mic. in thickness;
the threads of the interior thinner, about 2 mic. and smooth, or with
very minute scattered warts. Spores globose, even, 6-8 mic. in diameter.
See Plate I, Fig. 16.

Growing on old wood, mosses, etc. Capillitium 1-2 mm. long, the stipe
about the same length. It seems as common as _Arcyria cinerea_, and has
heretofore been included in it. See Massee's Monograph, p. 154.

7. ARCYRIA DIGITATA, Schw. Sporangium cylindric, the calyculus very
small. Stipe long, ascending, brownish in color, usually several
fasciculate or to some extent connate, the sporangia divergent at the
apex. Capillitium not much expanded after dehiscence, cylindric, pale
cinereous, or pale yellowish; the threads variable in thickness. 2-4
mic., those at the surface densely and minutely warted, those of the
interior nearly smooth. Spores globose, even, 6-8 mic. in diameter.

Growing on old wood. Capillitium 2-4 mm. long, the stipe about the same
length. _Arcyria bicolor_, B. & C.


III. HETEROTRICHIA, Massee. Sporangia regular, oblong-ovoid, stipitate;
the wall a thin delicate membrane, the upper part disappearing at
maturity, leaving the basal portion as a small calyculus. Stipe filled
with large thick-walled vesicles, which are sub-angular from mutual
pressure; these become smaller upward, and pass gradually into normal
spores. Capillitium issuing from the interior of the stipe, the central
and superficial threads dissimilar, forming a complicated network, with
numerous free extremities, the surface minutely warted, or with annular
ridges. Spores globose, brownish.

Distinguished from Arcyria by the numerous free extremities of the
peripheral portion of the network.

1. HETEROTRICHIA GABRIELLÆ, Massee. Sporangium oblong-ovoid, stipitate;
the calyculus small, thin, smooth. Stipe very short, erect,
yellowish-brown in color. Capillitium much elongated after dehiscence,
cylindric-ovoid, sub-erect; the threads of the central portion about 1.5
mic. thick, with slightly elevated ridges partly encircling the tube,
nearly colorless; threads of the peripheral portion bright yellow, 5-6
mic. thick, with numerous short acute free branches, the surface densely
and minutely warted. Spores in mass, yellowish-brown, globose, even, 7-8
mic. in diameter. See Plate I, Fig. 18.

Growing on wood; S. Carolina, _H. W. Ravenel_. The sporangia densely
crowded, becoming scattered toward the margin of the cluster. Massee's
Monograph of the Myxogasters.




ORDER V. TRICHIACEÆ.


Sporangium regular and stipitate or sessile, rarely plasmodiocarp; the
wall a thin membrane, usually granular or venulose on the inner surface,
colored as the spores and capillitium, irregularly dehiscent.
Capillitium of slender tubules, simple or branched, scarcely forming an
evident network; the surface of the threads furnished with continuous
ridges, which wind around the tube in a spiral manner. Spores globose,
red, brown, yellow, olivaceous.

This order is readily recognized by the spiral ridges which wind around
the tubules of the capillitium.

TABLE OF GENERA OF TRICHIACEÆ.

1. HEMIARCYRIA. Capillitium of long slender tubules, arising from the
base of the sporangium, or issuing from the interior of the stipe; the
spiral ridges parallel and conspicuous.

2. CALONEMA. Capillitium of slender tubules, arising from the base of
the sporangium; the surface traversed by a system of branching veins.

3. TRICHIA. Capillitium consisting of numerous short slender tubules,
called elaters, which are wholly free; the spiral ridges parallel and
conspicuous.

4. OLIGONEMA. Capillitium scanty, composed of elaters habitually
irregular and abnormal; the surface variously marked.


I. HEMIARCYRIA, Fr. Sporangia regular and stipitate, rarely
plasmodiocarp, the wall at maturity breaking away from above downward,
leaving more or less of the lower portion persistent. Stipe more or less
elongated, rarely wanting, resting on a thin hypothallus. Capillitium of
long slender tubules, more or less branched, arising from the base of
the sporangium, or issuing from the interior of the stipe; the spiral
ridges parallel and conspicuous, 3-5, rarely more in number, smooth or
spinulose. Spores globose, red, yellow.

The genus is related on the one hand to Arcyria by the mode of
attachment of the threads, on the other hand to Trichia, by the parallel
spiral ridges which wind around them. By the mode of branching of the
threads, the species fall readily into two sections.

§1. ARCYRIOIDES. Capillitium of slender threads, branching and
anastomosing, thus forming a more or less evident network.

In some of the species the large irregular meshes of the network are
scarcely to be discerned, but are rather to be inferred from the
abundant branching of the threads and the paucity of the free
extremities.

1. HEMIARCYRIA PLUMOSA, Morgan, n. sp. Sporangium obovoid to turbinate,
olive-yellow to olive-brown in color, stipitate; the wall densely
granulose within, externally smooth and shining, the upper part soon
disappearing, leaving a funnel-shaped persistent base. Stipe long,
erect, reddish-brown, arising from a thin hypothallus. Capillitium of
threads 5-7 mic. in thickness, repeatedly branched and anastomosing, to
form a dense network without any free extremities, olive-yellow to
olive-brown in color; the spiral ridges five or six, close, smooth.
Spores in mass, lemon-yellow, globose, very minutely warted, 8-9 mic. in
diameter. See Plate I, Fig. 19.

Growing gregariously on old damp logs; very common in this region.
Sporangium with the stipe 2-3 mm. in height, the stipe usually much
longer than the sporangium; the capillitium expands considerably after
the disappearance of the upper part of the sporangium. This species is
an Arcyria in every respect, except the spiral ridges, which wind about
the thread of the capillitium.

2. HEMIARCYRIA VARNEYI, Rex. Sporangium elongated ovoid, pale yellow,
stipitate; the upper part of the wall disappearing at maturity, leaving
a small cup-shaped persistent base. Stipe very short, dull brown.
Capillitium of very slender threads 3.2-3.5 mic. in thickness, dull
ochre in color, forming a network of small meshes, with numerous short
slightly clavate free extremities, which proceed from the peripheral
meshes; the spiral ridges seven or eight, winding unevenly, those of the
superficial threads minutely spinulose. Spores in mass pale yellow,
globose, even, 6-7 mic. in diameter.

Growing on old wood; Kansas, May Varney. Sporangium with the stipe about
1 mm. in height, the stipe very short. Dr. Rex, in Proceedings of the
Academy of Natural Sciences, Philadelphia, 1891.

3. HEMIARCYRIA ABLATA, Morgan n. sp. Sporangium obovoid to turbinate,
yellow or olive-yellow, stipitate; the wall rather firm, smooth and
shining, breaking away about the apex, leaving the greater portion
persistent. Stipe short, erect, yellow-brown to blackish in color,
arising from a thin hypothallus. Capillitium of threads, 5-7 mic. in
thickness, yellowish-ochre in color, more or less branched; the free
extremities very scarce, obtuse or slightly swollen; the spiral ridges
four or five, close, smooth or very minutely warted. Spores in mass,
yellow, globose, minutely warted, 8-9 mic. in diameter.

Growing on old wood of Elm, etc. Sporangium with the stipe 1.5-2.5 mm.
in height, the stipe variable in length, but not longer than the
sporangium, diameter of the sporangium .6-.8 mm. A half dozen threads
proceed from the inner wall of the stipe branch twenty-five or thirty
times, and afford scarcely half a dozen free ends.

4. HEMIARCYRIA STIPATA, Schw. Sporangia terete, elongated and flexuous,
closely packed together and lying upon one another, stipitate, from
bright incarnate to brick red or bay in color, smooth and shining; the
wall thin and fragile, soon disappearing, except a small cup-shaped
portion at the base. The stipes very short, often entirely concealed by
the dense mass of sporangia, arising from a common hypothallus.
Capillitium of threads somewhat variable in thickness, 3-6 mic.,
repeatedly branched and forming a network of very unequal meshes, with
occasional clavate free extremities, pale to dark red in color; the
spiral ridges three or four, often irregular, thickened or interrupted
by minute warts and spinules. Spores in mass incarnate to brownish-red,
globose, even, 7-9 mic. in diameter.

Growing on old wood of Liriodendron. Sporangia usually in small patches,
each 1-2 mic. in length, the stipe very thin and short.

§2. HEMITRICHIA. Capillitium of very long slender threads, simple or
remotely branched, and not forming a network, their further extremities
all free.

The threads of the capillitium in these species are usually much coiled
and entangled, but when straightened out they are seen to be very long,
but few in number, fixed at one end and free at the other.

5. HEMIARCYRIA LONGIFILA, Rex. Sporangium obovoid or pyriform, yellow,
stipitate; the wall a thin pellucid membrane, smooth and shining,
beautifully iridescent, breaking away above the middle, the lower
cup-shaped portion persistent. Stipe very short, reddish-brown to
blackish, arising from a common hypothallus. Capillitium of slender
threads, 3.5-4 mic. in thickness, golden yellow in color, simple or very
rarely branched; the free extremities obtuse or slightly swollen,
sometimes minutely apiculate; the spiral ridges, three or four, rather
distant, with very minute scattered spinules or nearly smooth. Spores in
mass, golden-yellow, globose, minutely warted, 9-10 mic. in diameter.

Growing on old wood of Oak, etc. Sporangium with the stipe .8-1.5 mm. in
height, the stipe very short, not exceeding the diameter of the
sporangium. A small species, distinguished by its golden-yellow spores
and capillitium.

6. HEMIARCYRIA FUNALIS, Morgan n. sp. Sporangium obovoid to turbinate,
yellow or olive yellow, polished stipitate; the wall firm, thickened on
the inner surface by an olivaceous layer, breaking away from above
downward, leaving an irregular cup-shaped base. Stipe short,
reddish-brown to blackish, arising from a thin hypothallus. Capillitium
of threads 6-8 mic. in thickness, yellowish-ochre or dull ochre in
color, simple or remotely branched; the free extremities obtuse or
swollen; the spiral ridges four or five, minutely warted. Spores in mass
yellow, globose, minutely warted, 8-9 mic. in diameter. See Plate I,
Fig. 20.

Growing on old wood. Sporangium 1.5-2.5 mm. in height, the stipe
variable, but usually much shorter than the sporangium. Scarcely to be
distinguished from _Hemiarcyria ablata_, except by the threads of the
capillitium.

7. HEMIARCYRIA RUBIFORMIS, Pers. Sporangium obovoid or turbinate to
cylindric, usually few to many fasciculate upon the united stipes,
sometimes sessile, brown-red to brown or blackish in color, smooth and
often shining with a metallic luster; the wall much thickened by a dense
brownish-red layer of minute granules, at maturity the apex torn away,
leaving much the greater part persistent. Capillitium of slender
threads, 4-6 mic. in thickness, brownish-red in color, very rarely
branched; the free extremities usually terminated by a stout spine; the
spiral ridges three or four, furnished with numerous spinules. Spores in
mass, brownish-red, globose, minutely warted, 9-11 mic. in diameter.

Growing on old wood; one of the commonest of the Myxomycetes. The
fascicle 3-4 mm. in height, the individual sporangia .5-.6 mm. in
diameter.

8. HEMIARCYRIA SERPULA, Scop. Plasmodiocarp terete, flexuous, usually
branching and anastomosing to form an extensive network, from tawny to
golden-yellow in color; the wall thin above and yellow, breaking open
irregularly and falling away down to the brownish thicker adherent
base. Capillitium consisting of a few long slender threads with
numerous scattered short branches, the threads 4-6 mic. in thickness,
golden-yellow; the free ends of the branches terminating in a slender
spine; the spiral ridges three or four, covered with numerous slender
spinules. Spores in the mass golden-yellow, globose, the surface
reticulate, 10-12 mic. in diameter.

Growing on and inside of rotten wood. Plasmodiocarp an irregular patch,
one to several centimeters in extent, the strands of the net about .5
mm. in thickness. A single reticulate plasmodium is usually converted
without change of form into an individual plasmodiocarp.


II. CALONEMA, Morgan, gen. nov. Sporangia subglobose, irregular,
sessile, without a hypothallus; the wall thin, marked with branching
veins, irregularly dehiscent. Capillitium of slender tubules, arising
from the base of the sporangium, repeatedly branched and with numerous
free extremities; the surface traversed by a system of branching veins,
ending in minute veinlets, which appear as irregular rings and spirals.
Spores subglobose, yellow.

The habit of the single species is that of an Oligonema, and it has
spores similar to those of most species of this genus, but the threads
are long and branched, and they are fastened below to the base of the
sporangium.

1. CALONEMA AUREUM, Morgan n. sp. Sporangia subglobose to turbinate,
sessile, closely crowded and from mutual pressure quite irregular; the
wall thin, marked with branching veins, golden-yellow in color, smooth
and shining. Capillitium of threads more or less branched, 5-6 mic. in
thickness, golden-yellow; the surface minutely venulose, and with larger
rings and spirals, and sometimes with scattered spinules; the free
extremities obtuse. Spores subglobose, yellow, the surface with elevated
ridges combined into a network, 14-16 mic. in diameter. See Plate I,
Fig. 21.

Growing on and within rotten wood. Sporangia quite irregular and
variable in size, .3-.6 mm. in diameter. The beautiful venation of the
wall of the sporangium is continued upon the surface of the threads of
the capillitium.


III. TRICHIA, Haller. Sporangia regular and stipitate or sessile and
somewhat irregular; the wall, at maturity, irregularly ruptured. The
stipe more or less elongated or often wanting, usually resting on a
hypothallus. Capillitium consisting of numerous short slender tubules,
called _elaters_, intermingled with the spores and wholly free; elaters
simple or rarely branched a time or two, each extremity terminating in a
smooth tapering point; the spiral ridges parallel and conspicuous, 2-5
in number, smooth or spinulose. Spores globose, yellow, ochraceous,
olivaceous.

The genus Trichia is unique among the Myxomycetes in having its
capillitium composed of tubules, which are entirely free from the wall
of the sporangium. The length of these free tubes varies usually between
.3 mm. and .5 mm., being sometimes shorter, but seldom longer; they are
typically cylindric, or equally thickened from end to end, or quite
rarely they are thickened in the middle, and taper gradually to each
extremity; the extremities terminate in a smooth tapering point,
straight or sometimes a little curved or flexuous, which maintains an
average length in each species. The spiral ridges wind around the thread
almost invariably to the left, or with the hands of a watch; they are
always more or less prominent and conspicuous, and usually maintain a
regular curve and uniform interval between each other in the same
species; their surface is either smooth, or sometimes it is invested
with minute warts or spinules.

In all the species of this genus, however, irregular and abnormal
elaters are occasionally met with among the typical ones. As these
abnormal forms always arrest attention, and have been conceived to
possess specific value, it may be well to note the principal of them.

1. The elater is sometimes branched. In two or three species the
branching appears to be quite regular and not abnormal; still, even in
these species, most of the elaters in the sporangia are not branched. In
some cases the branching arises from confluence of two or more elaters.

2. Ellipsoidal swellings, or enlargements of the elater, sometimes
occur, at one or both extremities, or at points intermediate between
them; these always occur irregularly, and are essentially abnormal.

3. The smooth tapering point is rarely wanting, in which case the
extremity presents a blunt end, the spiral ridges running to the end.
More frequently the tapering points are multiplied, the elaters bearing
two or three spines at the extremities; this often occurs in the species
of Trichia, and also of Hemiarcyria with spinulose elaters.

4. The spiral ridges are sometimes defective, there being less than the
typical number; sometimes they are merely displaced, there being a much
wider interval between them than usual; rarely do they habitually wind
about the thread in an irregular manner.

5. Under high magnifying power, fine ridges are sometimes seen running
lengthwise of the elaters, bridging the intervals between the spirals.
These were first observed by DeBary, in _Trichia chrysosperma_, but they
have since been seen in the elaters of nearly every other species of
Trichia, and also in species of Hemiarcyria.

The few species with elaters, so far as yet known, habitually irregular,
defective and abnormal, are referred to the genus Oligonema.

The normal species of Trichia arrange themselves quite naturally into
three sections.

§1. A NACTIUM. Sporangia varying from globose to pyriform or turbinate,
supported on a more or less elongated stipe. Spores globose, the surface
minutely warted.

_a. Elaters with very long tapering extremities._

1. TRICHIA FRAGILIS, Sow. Sporangia obovoid to pyriform or clavate,
often fasciculate, stipitate; the wall a thin membrane, with a thick
dense outer layer of brown-red granules. Stipes long, erect or curved,
simple or usually fasciculate and often connate, arising from a thin
hypothallus. Mass of spores and capillitium from reddish-brown to yellow
and ochraceous; elaters simple, rarely branched, 4-5 mic. thick, with
very long tapering extremities, ending in smooth points 8-12 mic. long;
spirals, three or four, perfectly smooth. Spores globose, minutely
warted, 10-12 mic. in diameter.

Growing on old wood. Sporangia with the stipe 2-4 mm. in height, the
sporangium .6-.8 mm. in diameter, the stipe usually longer than the
sporangium. The color quite variable, mostly dull red-brown or
blackish-brown, more rarely yellow or coffee-brown, usually opaque,
rarely shining.

2. TRICHIA FALLAX, Pers. Sporangium obovoid to pyriform or turbinate,
rarely clavate, stipitate; the wall thin, smooth and shining, colored as
the spores and capillitium. Stipe more or less elongated, simple, erect,
brownish below, filled with roundish vesicles. Mass of capillitium and
spores yellowish, ochraceous or olivaceous; elaters simple or sometimes
with several branches, 4-6 mic. thick in the middle, tapering gradually
to each extremity, ending in smooth tapering points, 20-40 mic. in
length; spirals, three, perfectly smooth. Spores globose, minutely
warted, 10-12 mic. in diameter. See Plate I, Fig. 22.

Growing on old wood. Sporangium with the stipe 2-4 mm. in height,
sporangium .6-.8 mm. in diameter, the stipe usually longer than the
sporangium. Under high magnifying power the spores are seen to be
minutely reticulated.

_b. Elaters cylindric, ending in a smooth tapering point._

3. TRICHIA SUBFUSCA, Rex. Sporangium globose, rarely globose-turbinate,
stipitate; the wall thickish, dull tawny-brown above, shading to dark
brown at the base. Stipe simple, erect, brown or blackish in color. Mass
of capillitium and spores bright yellow; elaters simple, rarely
branched, cylindric, 3.5-4 mic. in thickness, ending in smooth tapering
points, 10-12 mic. in length; spirals, four in number, perfectly smooth.
Spores globose, minutely warted, 11.5-12.5 mic. in diameter.

On old wood and bark, Adirondack Mountains, New York. Dr. George A. Rex.
Sporangium .5-.8 mm. in diameter, the stipe equal in height to the
diameter of the sporangium.

4. TRICHIA ERECTA, Rex. Sporangium globose to globose-turbinate,
stipitate; the wall of both sporangium and stipe with a rough outer
layer of brown scales and granules, which, on the upper surface of the
sporangium, soon breaks up into irregular patches. Stipes long, erect,
usually simple, rarely fasciculate and connate. Mass of capillitium and
spores, bright yellow; elaters simple, cylindric, 4 mic. in thickness,
ending in smooth points, 4-6 mic. long; spirals four, often united by
intervening branches, covered with numerous irregular spinules. Spores
globose, minutely warted, 12-14 mic. in diameter.

Growing on old wood and bark, Adirondack Mountains, New York, Dr. Geo.
A. Rex. Sporangium .5-.8 mm. in diameter, the stipe about 1 mm. in
height. This Trichia is conspicuous by the checkering or areolation of
the upper surface in the mature sporangia, affording a sharp contrast
between the brown patches and the yellow bands.

§2. CHRYSOPHIDIA. Sporangia globose, obovoid or somewhat irregular,
sessile, rarely with a short stipe, usually closely crowded. Spores
globose, the surface minutely warted.

_a. Elaters perfectly smooth._

5. TRICHIA VARIA, Pers. Sporangia globose, obovoid or somewhat
irregular, gregarious and scattered or crowded, yellowish, ochraceous or
olivaceous, sessile, or with a very short brown or blackish stipe. Mass
of capillitium and spores yellow; elaters long, simple or sometimes
branched a time or two, 4-5 mic. in thickness, ending in a smooth
tapering point, 8-12 mic. long; spirals only two, smooth, very prominent
in places, causing the elater to appear notched. Spores globose, oval or
somewhat irregular, minutely warted, 10-14 mic. in diameter.

Growing in patches on old wood; a very common species. Sporangium .6-.8
mm. in diameter, or when irregular sometimes elongated to 1 mm. or more.
Extremely variable as to the form of the sporangium, but readily
recognized by its elaters.

6. TRICHIA ANDERSONI, Rex. Sporangia globose or obovoid, sessile,
gregarious, closely crowded, or sometimes scattered, the wall thickened
with minute scales, in color brownish-ochre or olivaceous. Mass of
capillitium and spores yellow; elaters long, simple, 3-4 mic. in
thickness, ending in a very long flexuous point, 14-18 mic. in length;
spirals three or four, winding evenly and closely, perfectly smooth.
Spores globose, minutely warted, 10-12 mic. in diameter.

Growing on the inside of bark of Acer. Sporangium .4-.5 mm. in diameter.
The capillitium is deep orange and the spores olivaceous, but this
difference in shade of color between spores and capillitium occurs in
other species. _Trichia advenula_, Mass., is a closely related species,
the swellings in the elaters having no specific value.

7. TRICHIA INCONSPICUA, Rost. Sporangia very small, subglobose, sessile,
collected together in clusters, or scattered, without any hypothallus;
the wall brown, smooth and shining. Mass of capillitium and spores
yellow; elaters long, simple, cylindric, 3-4 mic. in thickness, ending
in smooth tapering points, 6-7 mic. in length; spirals three or four,
close, not prominent, perfectly smooth. Spores globose, minutely warted,
10-12 mic. in diameter.

Growing on bark of Platanus, etc. New York, _Peck_; Iowa, _McBride_. The
sporangia spherical or reniform and very small.

_b. Elaters spinulose._

8. TRICHIA IOWENSIS, McBride. Sporangia subglobose, sessile, gregarious,
scattered, or sometimes close and confluent; the wall thickened with
minute scales, reddish-brown in color. Mass of capillitium and spores
yellow; elaters quite variable, usually very long, but sometimes very
short, simple, rarely branched, the thickness unequal, 3-4 mic. in the
same elater, with occasional thicker swellings, bearing numerous
scattered spines, usually about as long as the thickness of the elater,
but sometimes much longer, those at the ends being similar; spirals
three or four, fine and close, in places nearly obsolete. Spores
globose, or more or less irregular, minutely warted, 9-11 mic. in
diameter.

Growing on old bark of Populus; Iowa, McBride. Sporangia .4-.5 mm. in
diameter. This is a very curious species of Trichia; it suggests
_Ophiotheca Wrightii_, but the elaters are short and simple, and there
is no question as to the spirals upon them. I could find no branched
elaters in my specimen.

9. TRICHIA SCABRA, Rost. Sporangia globose or somewhat irregular,
sessile and closely crowded on a well-developed hypothallus; the wall
thin, gold-yellow or orange to yellow-brown in color, smooth and
shining. Mass of capillitium and spores orange or golden-yellow; elaters
long, simple, 4-5 mic. in thickness, ending in a smooth tapering point,
5-8 mic. in length; spirals three or four, covered with numerous short
acute spinules. Spores globose, minutely warted, 9-11 mic. in diameter.
See Plate I, Fig. 23.

Growing on old wood in patches, sometimes several centimeters in extent.
Sporangia .6-1 mm. in diameter. "The papillæ, which cover the spore,
show, when highly magnified, a distinct net-like pattern," _McBride_.
The elaters of this species are subject to much irregularity in the way
of abnormal swellings, duplicating the spines at the apex, etc.; the
spinules are sometimes quite obsolete on some or all of the elaters of a
sporangium.

§3. GONIOSPORA, Fr. Sporangia obovoid to oblong, sessile and closely
crowded on a well-developed common hypothallus. Spores with thick ridges
upon the surface, which are combined into a more or less incomplete
network of polygonal meshes.

The ridges of the epispore are 1-2 mic. in height, and do not present to
the view more than two or three perfect polygons on a hemisphere of the
spores; more often the reticulation is imperfect, the ridges being
interrupted and defective. When highly magnified these ridges are seen
to be "perforated through their thickness with one, two or three rows,
or with clusters of cylindrical openings or pits, or are sculptured into
intricate plexuses of minute reticulations with quadrilateral
interspaces."

10. TRICHIA AFFINIS, DeB. Sporangia obovoid to oblong, sessile and
closely crowded on a common hypothallus; the wall thin, golden-yellow to
tawny or brownish-yellow, smooth and shining. Mass of capillitium and
spores golden to tawny-yellow; elaters long, simple, 4-5 mic. in
thickness, ending in a smooth tapering point, 6-10 mic. in length;
spirals four, usually spinulose, rarely smooth. Spores angularly or
irregularly globose, 10-12 mic. in diameter.

Growing on old wood and bark in small patches of a few millimeters to a
centimeter or more in extent. Sporangia .6-.8 mm. in height by .4-.5 mm.
in diameter. _Trichia Jackii_, Rost., is included in this species.

11. TRICHIA CHRYSOSPERMA, Bull. Sporangia oblong-obovoid to cylindric,
sessile and closely crowded on a well-developed hypothallus; the wall
thin, pale citron to olive-yellow, smooth and shining. Mass of
capillitium and spores, golden to ochre-yellow; elaters long, simple,
6-8 mic. in thickness, ending in a smooth tapering point, 3-7 mic. in
length; spirals four or five, usually smooth, rarely spinulose. Spores
angularly or irregularly globose, 12-14 mic. in diameter.

Growing on old wood, in small patches, one to several centimeters in
extent. Sporangia 1-2 mm. in height and .5-.6 mm. in diameter. This is
readily distinguished from _Trichia affinis_ by the larger and
differently colored sporangia.


IV. OLIGONEMA, Rost. Sporangia subglobose, more or less irregular,
sessile and closely crowded, often in heaps, one upon another, the wall
thin, smooth and shining; hypothallus none. Capillitium scanty, composed
of elaters habitually irregular and abnormal, intermingled with the
spores; elaters simple or sometimes branched, commonly very short, but
varying greatly in length, even in the same sporangium; the surface
marked with faint spirals, with a few annular ridges, minutely
punctulate or altogether smooth. Spores globose, yellow.

The species of this genus are to be regarded as degenerate Trichias. Of
course, the abnormality is exhibited most markedly by the elaters;
nevertheless, the sporangia of some of the species have a peculiar habit
of heaping themselves upon each other.

_A. Surface of the spores reticulate._

_a. Elaters with projecting rings._

1. OLIGONEMA NITENS, Lib. Sporangia subglobose, irregular, sessile,
closely crowded and heaped upon each other, the wall thin, yellow,
smooth and shining. Mass of capillitium and spores yellow; elaters
simple or sometimes branched, 3-4 mic. in thickness, with a few distant
projecting rings, the surface smooth between, or with very faint
spirals, the extremities obtuse, or sometimes with a minute apiculus.
Spores angularly or irregularly globose, the surface reticulate, 11-14
mic. in diameter.

Growing in small patches on and within rotten wood. Sporangia .4-.5 mm.
in diameter; the elaters variable, some with as many as a dozen
projecting rings, some with but a few or nearly smooth. _Trichia
nitens_, Libert.

2. OLIGONEMA PUSILLA, Schr. Sporangia subglobose, irregular, sessile,
scattered or collected together in heaps; the wall thin, yellow, smooth
and shining. Mass of capillitium and spores yellow; elaters simple or
sometimes branched, 4 mic. in thickness, sometimes with thicker inflated
portions, the surface marked with low faint spirals or perfectly smooth;
the extremities rounded and usually terminating in a smooth point, 3-5
mic. in length--this point either curved, bent to one side or turned
back, and twisted around the extremity as a ring. Spores angularly or
irregularly globose, the surface reticulate, 11-14 mic. in diameter.

Growing in small clusters in rotten wood. Sporangia .3-.5 mm. in
diameter; the elaters variable in length, scarcely exceeding 100 mic.
and often much shorter. _Trichia pusilla_, Schroeter.

_b. Elaters with no projecting rings._

3. OLIGONEMA FLAVIDUM, Peck. Sporangia obovoid to oblong, sessile,
closely crowded and irregular from mutual pressure; the wall thin,
yellow, shining, punctulate or minutely granulose. Mass of spores and
capillitium yellow; elaters simple or sometimes branched, 3-4 mic. in
thickness, sometimes with thicker inflated portions; the surface
punctulate or minutely warted, occasionally marked with very faint
spirals; the extremities usually rounded and obtuse, sometimes acute,
and rarely with a minute apiculus. Spores angularly or irregularly
globose, the surface reticulate, 11-14 mic. in diameter. See Plate I,
Fig. 24.

Growing in dense patches on old wood and mosses. Sporangia .4-.6 mm. in
diameter, and reaching 1 mm. in height, the elaters usually rather long,
sometimes quite long and branched.

4. OLIGONEMA BREVIFILA, Peck. Sporangia subglobose, irregular, sessile,
crowded, forming clusters or effused patches; the wall thin, yellow,
densely granulose and venulose. Mass of capillitium and spores
ochre-yellow; elaters simple or sometimes branched, often very short and
fusiform, when elongated having long tapering extremities, sometimes
with irregular swollen portions; the surface minutely granulose and
rugulose, here and there a few spinules, occasionally with indistinct
spirals. Spores angularly or irregularly globose, the surface
reticulate, 11-12 mic. in diameter.

Growing on old wood and mosses. Sporangia .4-.5 mic. in diameter, the
elaters varying greatly in length, some not more than 20 or 30 mic.
long, others more than 100 mic. in length.

_B. Spores minutely warted._

5. OLIGONEMA FULVUM, Morgan n. sp. Sporangia rather large, subglobose,
sessile, closely crowded and more or less irregular; the wall tawny
yellow, very thin and fragile, smooth, shining and iridescent. Mass of
capillitium and spores tawny yellow; elaters simple or sometimes
branched, mostly very short, 4 mic. in thickness, sometimes with thicker
swollen portions; the surface marked with low smooth spirals, in places
faint and obsolete; the extremities rounded and obtuse, usually with a
very minute apiculus, 1-3 mic. in length. Spores globose, minutely
warted, 10-13 mic. in diameter.

Growing on an old effused Sphæria. Sporangia .6-.8 mm. in diameter, the
elaters mostly 40-80 mic. in length, rarely much longer and sometimes
shorter; the longer elaters and those that are branched often arise from
confluence of the shorter ones.


EXPLANATION OF PLATE I.

Fig. 13.--Perichæna depressa, Lib.

Fig. 14.--Ophiotheca Wrightii, B. & C.

Fig. 15.--Lachnobolus globosus, Schw.

Fig. 16.--Arcyria Cookei, Massee.

Fig. 17.--Arcyria minor, Schw.

Fig. 18.--Heterotrichia Gabriellæ, Massee. (After Massee.)

Fig. 19.--Hemiarcyria plumosa, Morgan.

Fig. 20.--Hemiarcyria funalis, Morgan.

Fig. 21.--Calonema aureum, Morgan.

Fig. 22.--Trichia fallax, Pers.

Fig. 23.--Trichia scabra, Rost.

Fig. 24.--Oligonema flavidum, Peck.

NOTE.--Each figure exhibits the sporangium as it appears magnified about
100 diameters, and the capillitium and spores magnified about 500
diameters.

[Illustration: The Journal of the Cin. Soc. Natural History.

  VOL. XVI.                                         PLATE I.]

       *       *       *       *       *

THE MYXOMYCETES OF THE MIAMI VALLEY, OHIO.

BY A. P. MORGAN.

Third Paper.

(Read February 6, 1894.)




ORDER VI. STEMONITACEÆ.


Sporangia globose or ovoid to oblong and cylindrical, stipitate; the
wall very thin and fragile, soon disappearing. Stipe tapering upward and
continued within the sporangium as a more or less elongated columella.
Capillitium of slender brown threads, arising from numerous points of
the columella, repeatedly branching and usually anastomosing to form a
network, persistent and rigidly preserving the outline of the
sporangium. Spores globose, brown or violaceous.

This order is readily distinguished by the brown persistent capillitium,
arising from a lengthened columella, and rigidly maintaining the form of
the sporangium.

Table of Genera of Stemonitaceæ.

_A. Stipe and columella brown or black._

_a. The columella scarcely reaching the center of the sporangium._

1. CLASTODERMA. Threads of the capillitium forking several times, but
not combined into a network.

2. LAMPRODERMA. Threads of the capillitium branching and anastomosing to
form a network.

_b. The columella extending beyond the center of the sporangium._

3. COMATRICHA. Threads of the capillitium forming only an interior
network, attaining the wall by numerous more or less elongated free
extremities.

4. STEMONITIS. Threads of the capillitium forming an interior network of
large meshes and a superficial network of smaller meshes.

5. ENERTHENEMA. Threads of the capillitium pendent from a discoid
membrane at the apex of the columella.

_B. Stipe and columella white or yellowish._

6. DIACHAEA. Threads of the capillitium branching and anastomosing to
form a network.


I. CLASTODERMA, Blytt. Sporangium regular, globose, stipitate; the wall
very thin and fragile. Stipe elongated, tapering upward, entering the
sporangium as a very short or nearly obsolete columella. Capillitium
arising by a few branches from the apex of the columella, these branches
forking several times at a sharp angle, but not combined into a network,
the ultimate branchlets long and free, or only connected together at
their tips by persistent fragments of the sporangial wall. Spores
globose, violaceous.

The claim of this genus to be distinguished from Lamproderma must rest
upon the fact that the branchlets of the capillitium do not anastomose
and form a network. It is the same as the genus Orthotricha of Wingate.

1. CLASTODERMA DE BARYANUM, Blytt. Sporangium very small, globose; the
wall early disappearing, except the minute fragments which persist at
the extremities of the capillitium, and a narrow collar at the base of
the columella. Stipe very long, thick and brown below, tapering upward
to a pellucid oblong swelling, thence abruptly narrowed to the apex; the
columella extremely short, capillitium of very slender pale-brown
semi-pellucid threads, divergently forking, the ultimate branchlets
often joined 2-4 together at their tips by fragments of the sporangial
wall. Spores globose, even, violaceous, 8-9 mic. in diameter. See Plate
XI, Fig. 25.

Growing in rather a scattered way on old rotten wood. Sporangium .20-.25
mm. in diameter, the stipe .7-1.3 mm. long. _Orthotricha microcephala_,
Wingate. Blytt's species was found in Norway, Wingate's in Pennsylvania;
I have met with it several times in this locality. It is possibly more
common than it appears, as by reason of the difficulty of seeing the
minute sporangium it is passed by as some mold. Blytt's spore
measurements are 9.5-11 mic.; in some specimens I have seen a few spores
of this size, but they are abnormal.


II. LAMPRODERMA, Rost. Sporangia regular, globose, stipitate; the wall
thin and fragile, rugulose, shining with metallic tints, breaking up
irregularly and gradually falling away. Stipe more or less elongated,
smooth, brown or black in color, arising from a hypothallus, tapering
upward and entering the sporangium as a short columella scarcely
reaching the center. Capillitium of numerous threads radiating from the
columella, usually forking several times and combined into a net by
lateral anastomosing branchlets. Spores globose, brown or violaceous.

Lamproderma is distinguished by the shining metallic tints of the
sporangial wall, and by the short columella scarcely reaching half the
height of the sporangium.

1. LAMPRODERMA PHYSAROIDES, A. & S. Sporangium globose; the wall with a
silvery metallic luster, at length breaking up and falling away. Stipe
long, slender, brown or blackish, arising from a small circular
hypothallus; columella clavate, obtuse, not reaching the center of the
sporangium. Capillitium of brownish-violet threads, arising from the
upper part of the columella; these branch repeatedly at a sharp angle,
form an intricate network of elongated meshes, terminating at the wall
in numerous short free branchlets. Spores globose, minutely warted,
bright brown, 12-14 mic. in diameter.

Growing on old wood, moss, etc., New York, _Chas. H. Peck_.
Distinguished by the pale silvery sporangial wall and the clear brown
spores.

2. LAMPRODERMA ARCYRIONEMA, Rost. Sporangium small, globose; the wall
dark bronze, with a silvery sheen when loosened from the spores, soon
breaking into scales and falling away. Stipe long and slender, smooth,
shining and black, rising from a thin hypothallus; the columella short
cylindric, variable in length, but not attaining the center of the
sporangium. Capillitium arising by division of the apex of the columella
into several primary branches; these immediately separate into numerous
slender flexuous brown threads, which unite and form a dense network of
small arcuate meshes, the ultimate branchlets not free. Spores globose,
even, violaceous, 6-7 mic. in diameter. See plate XI, Fig. 26.

Growing on old wood of Juglans and Carya. Sporangium .3-.5 mm. in
diameter, the stipe three or four times as long. The columella is
somewhat variable, it sometimes forks or divides immediately on entering
the sporangium, at other times it is longer and cylindric, with more
slender primary branches. The meshes of the capillitium resemble those
of Arcyria, whence the name. This is the _Stemonitis physaroides_, A. &
S. var. _suboeneus_ of Lea's Catalogue.

3. LAMPRODERMA VIOLACEUM, Fr. Sporangium depressed-globose, convex above
and more or less flattened and umbilicate beneath; the wall shining with
steel or violet, blue and purple tints, deciduous. Stipe short, stout,
brown or blackish in color, arising from a thin, brown, common
hypothallus; columella cylindric, or tapering slightly to an obtuse
apex, attaining the center of the sporangium. Capillitium of numerous
slender threads, radiating from the upper part of the columella; these
threads are brown below, with a variable outer portion colorless; they
branch a few times and form an interior network of elongated meshes,
outwardly arching and freely anastomosing they give rise to an external
network of small irregular meshes, they then attain the wall by
innumerable short, simple, or forked free branchlets. Spores globose,
minutely spinulose, violaceous, 9-11 mic. in diameter. See plate XI, Fig
27.

Growing on old wood, mosses, etc., late in Autumn. Sporangium .5-.8 mm.
in diameter, the stipe about the same length. The capillitium is
sometimes most of it colorless and flaccid; sometimes it is all brown
and rigid except the minute free extremities.

4. LAMPRODERMA ARCYRIOIDES, Somm. Sporangium globose or ellipsoid, and
somewhat elongated; the wall with tints of violet, purple, and blue,
deciduous. Stipe usually short, or sometimes nearly obsolete, brown or
blackish in color, arising from a strongly-developed hypothallus; the
columella cylindric or slightly tapering upward, and obtuse, reaching
nearly to the center of the sporangium. Capillitium of numerous
pale-brown threads, radiating from the apex of the columella; these fork
directly from the base, are bent and flexuous, and are combined into a
dense, intricate net, with abundant free extremities. Spores globose,
spinulose, violaceous, 13-16 mic. in diameter.

Growing on old leaves, wood, etc. Sporangium .5-.8 mm. in diameter, the
stipe variable in length from very short to 1 mm. long or beyond.
_Lamproderma columbinum_, Pers. is a doubtful species, the forms of that
name being easily distributed between the present species and _L.
physaroides_.

5. LAMPRODERMA SCINTILLANS, B. & Br. Sporangium globose; the wall
shining with colors of blue, purple, and bronze, deciduous. Stipe long,
slender, smooth, and shining, brown or blackish, rising from a thin,
brown, common hypothallus; columella cylindric or slightly tapering to
the obtuse apex, not reaching the center of the sporangium. Capillitium
of numerous brown threads, originating about the apex of the columella;
these fork several times, with few anastomosing branchlets, and
terminate at the wall in long, free extremities. Spores globose,
minutely warted, violaceous, 7-9 mic. in diameter. See Plate XI, Fig.
28.

Growing on old leaves, moss, etc., in early Spring. Sporangium .3-.5 mm.
in diameter, the stipe from once to twice as long. This is _Lamproderma
irideum_ of Massee's Monograph. I am indebted to Arthur Lister, Esq., of
London, for the identification of my specimens with _Stemonitis
scintillans_, B. & Br., and with _Lamproderma irideum_, Cke.


III. COMATRICHA, Preuss. Sporangia various in shape, from globose or
ovoid to oblong and cylindric, stipitate; the wall very thin and
fugacious. Stipe more or less elongated, smooth and black, arising from
a common hypothallus, tapering upward, entering the sporangium and
prolonged nearly or quite to the apex as a columella. Capillitium
arising from numerous points of the columella throughout its entire
length; the threads immediately branching and anastomosing to form an
interior network, attaining the wall by numerous more or less elongated
free extremities. Spores globose, brown or violaceous.

This genus is not sharply limited from Stemonitis. The species with very
short free ends, and consequently with superficial meshes approximate to
the wall, are near the form of Stemonitis. But it may be observed that
in these species, the meshes of the capillitium become smaller gradually
outward, the sides of the superficial meshes are arched away from the
wall, and they are in contact with it only by the free extremities.

§1. TYPHOIDES. Threads of the capillitium repeatedly branching and
anastomosing, to form a dense network of small meshes, with innumerable
short, free extremities.

1. COMATRICHA TYPHINA, Roth. Sporangia short, erect or a little curved,
cylindric or usually narrowing slightly upward, the base quite blunt,
the apex more rounded, growing together on a thin hypothallus. Stipe and
columella brown or blackish, tapering upward and vanishing near the apex
of the sporangium, the stipe much shorter than the columella.
Capillitium of slender flexuous tawny-brown threads; these branch
repeatedly, forming an intricate network of small irregular meshes,
ending in very short free extremities. Spores globose, violaceous, very
minutely warted, 6-8 mic. in diameter.

Growing on old wood, mosses, etc. Sporangium with the stipe 2-4 mm. in
height, the stipe much the shorter, the sporangium .35-.40 mm. in
thickness. _Stemonitis typhoides_, Fries, S. M.

2. COMATRICHA ÆQUALIS, Pk. Sporangia usually more or less inclined or
curved and nodding, cylindric, obtuse at each end, growing together on a
thin hypothallus. Stipe and columella slender, smooth, black, extending
nearly or quite to the apex of the sporangium, the stipe longer than the
columella. Capillitium of very slender flexuous tawny-brown threads;
these branch repeatedly, forming an intricate network of small irregular
meshes, ending in very short free extremities. Spores globose, minutely
warted, dark violaceous, 7-9 mic. in diameter.

Growing on old wood. Sporangium 1.5-3 mm. in height by .35-.40 mm. in
thickness, the stipe usually about the same length as the sporangium,
but sometimes nearly twice as long. The capillitium is rather looser
than in _C. typhina_, whence the drooping habit. Peck, Thirty-first
Report, p. 42.

3. COMATRICHA NIGRA, Pers. Sporangia globose or ovoid to ellipsoid or
oblong, erect or sometimes inclined or even nodding. The stipe very
long, smooth and black, tapering upward, expanding at the base into a
small circular hypothallus; the columella short, reaching from one-half
to three-fourths the height of the sporangium. Capillitium of slender
flexuous brown threads, which branch repeatedly, forming a dense
intricate network of small meshes, ending in very short free
extremities. Spores globose, even, dark violaceous, 8-10 mic. in
diameter.

Growing on old wood, leaves, etc. Sporangium .5-1.5 mm. in height, .5-.8
mm. in diameter, the stipe 1.5-3 mm. long or sometimes considerably
longer. This species seems to be rare in this country. I have preferred
the name adopted by Schroeter to Rostafinski's _Comatricha Friesiana_.

4. COMATRICHA ELLISII, Morgan, n. sp. Sporangia short, erect, oval or
ovoid to oblong. Stipe and columella erect, brown and smooth, rising
from a thin pallid hypothallus, tapering upward and vanishing into the
capillitium toward the apex of the sporangium, the stipe usually longer
than the columella. Capillitium of slender pale brown threads; these
branch several times with lateral anastomosing branchlets, forming a
rather open network of small meshes, ending with very short free
extremities. Spores globose, even, pale ochraceous, 6-7 mic. in
diameter. See Plate XI, Fig. 29.

Growing on old pine wood. Sporangium .3-.6 mm. in height by .3-.5 mm. in
width, the stipe usually a little longer than the sporangium. This
elegant little species I have from Mr. J. B. Ellis, of Newfield, N. J.
It is said to be mingled in some of the specimens with _Lamproderma
Ellisiana_, Cke.

§2. LARVELLA. Threads of the capillitium branching a few times and
anastomosing to form a network of large meshes, attaining the wall by
numerous long, free extremities.

5. COMATRICHA CRYPTA, Schw. Sporangia cylindric, bent or flexuous and
more or less inclined, growing close together on a conspicuous
purplish-brown hypothallus. Stipe and columella smooth and black,
tapering upward and reaching the apex of the sporangium, the columella
bent and flexuous or spirally twisted, about as long as the stipe.
Capillitium composed of irregular, bent and uneven threads, which are
brown below, becoming colorless outwardly; the threads branch a few
times, forming a network of large irregular meshes, sometimes much
defective; the free extremities irregular and unequal, simple or
branched. Spores globose, brown, minutely warted, 7-9 mic. in diameter.
See Plate XI, Fig. 30.

Growing out of fissures of the bark and wood of Hickory, Acer, etc.
Sporangium with the stipe 4-7 mm. in height, the stipe a little shorter,
or sometimes much longer than the sporangium, the latter .25-.30 mm. in
thickness. The exterior colorless portion of the capillitium is
exceedingly delicate, easily breaking away and leaving the capillitium
quite irregular and defective. _Stemonitis crypta_, Schweinitz's N. A.
Fungi, 2351. _Comatricha irregularis_, Rex, is the same thing.

6. COMATRICHA CÆSPITOSA, Sturgis. Sporangia short, clavate, densely
crowded or cæspitose upon a delicate hypothallus; the wall
subpersistent, silvery, shining with tints of purple and blue. Stipe
very short or nearly obsolete, the columella rising to two-thirds or
three-fourths the height of the sporangium. Capillitium of slender
dark-brown threads, which branch and anastomose quite irregularly,
forming a network of intermingled large and small meshes, ending in
long, tapering, free extremities. Spores globose, minutely spinulose,
dark violaceous, 10-12 mic. in diameter.

Growing on moss and lichens, at Wood's Holl, Massachusetts. Sporangium
1-1.5 mm. in height, the stipe very short or sometimes apparently
wanting. I am indebted to Dr. W. C. Sturgis, of New Haven, Conn., for a
specimen of this unique species.

7. COMATRICHA LONGA, Peck. Sporangia very slender and much elongated,
tapering gradually upward, weak and prostrate or pendulous, growing
close together on a well-developed purplish-black hypothallus. Stipe and
columella capillary, smooth and black, reaching to the apex of the
sporangium or often vanishing in the network far below it, the stipe
very short, the columella long and flexible. Capillitium of long,
slender, dark-brown threads; these are reticulately connected near the
base, forming a network of large irregular meshes in a series along the
columella; outwardly they are terminated by very long free branchlets,
which vary from simple to two or three times forked or branched. Spores
globose, minutely warted, dark brown, 8-10 mic. in diameter. See Plate
XI, Fig. 31.

Growing on old wood and bark of Elm, Willow, etc., in Autumn. Sporangium
with the stipe 15-40 mm. in length, the stipe 3-8 mm. long, the
sporangium .25-.40 mm. in thickness. This is the most characteristic
species of the genus, being farthest removed from Stemonitis.

8. COMATRICHA FLACCIDA, Lister. Sporangia growing closely crowded
together and more or less confluent, on a purplish-brown hypothallus,
the walls fugacious. Columellas rising simply from the common
hypothallus, or sometimes grown together below and then apparently
branching, running through to the apex, and there often confluent with
each other, or joined together by portions of membrane. Capillitium of
slender brown threads, which branch and anastomose very irregularly,
forming a ragged network with large irregular meshes, and long free
extremities; the capillitium of adjoining columellas being much
entangled, and often confluent or grown together. Spores globose, very
minutely warted, brown, 7-9 mic. in diameter.

Growing on old wood and bark of Oak, Willow, etc. The component
sporangia 5-10 mm. in length. The early appearance is much like that of
species of Stemonitis, but the mature stage is a great mass of spores
with scanty capillitium, as in Reticularia; the columellas, however, are
genuine and not adjacent portions of wall grown together. Arthur Lister
calls this _Stemonitis splendens_, var. _flaccida_.


IV. STEMONITIS, Gled. Sporangia subcylindric, elongated, stipitate,
standing close together on a well-developed common hypothallus, the wall
very thin and evanescent. Stipe brown or black, smooth and shining,
tapering upward, entering the sporangium and prolonged nearly to the
apex as a slender columella, the stipe shorter than the columella.
Capillitium arising from numerous points of the columella throughout its
entire length; the threads immediately branch and anastomose to form an
interior network of large meshes, they then spread out next the wall of
the sporangium into a superficial network of smaller meshes. Spores
globose, brown or violaceous.

In this genus there are two distinctly differentiated series in the
capillitium, the one an interior supporting network of large meshes, the
other a superficial network of smaller meshes; sometimes the superficial
network disappears or is wanting toward the upper part of the
capillitium, there is then an approach to Comatricha. Very minute
scattered branchlets usually connect the superficial network with the
wall of the sporangium.

§1. DICTYNNA. Threads of the capillitium arising from numerous points of
the columella, immediately branching several times and anastomosing to
form the interior network of large meshes; the superficial network
consisting of small irregular and unequal meshes, varying from smaller
than the spores to two or three times their diameter.

1. STEMONITIS FUSCA, Roth. Sporangia elongated, subcylindric, tapering
and obtuse at the apex, tapering gradually downward, growing closely
crowded together on a strongly-developed brown hypothallus. Stipe and
columella smooth and black, tapering gradually upward and disappearing
near the apex of the sporangium, the stipe shorter than the columella.
Capillitium of slender brown or blackish threads, which immediately
branch and anastomose, forming a dense interior network of large
irregular meshes, the ultimate branchlets of which support a superficial
network of small polygonal meshes. Spores globose, dark violaceous, the
surface minutely warted, the warts with a reticulate arrangement, 7-9
mic. in diameter.

Growing on old wood, bark, leaves, etc.; common everywhere. Sporangium
with the stipe 6-15 mm. in height, the sporangium .3-.4 mm. in
thickness, the stipe variable in length, but always shorter than the
sporangium. The meshes of the superficial net vary in size in the same
sporangium, being usually 5-25 mic. in width, but sometimes they are
larger, ranging from 10-40 mic. in extent. The name _Stemonitis maxima_
was given by Schweinitz to some unusually large specimens which grew on
a Polyporus. _Stemonitis dictyospora_ of Rostafinski's monograph, with
spores 12 mic. in diameter, is said to occur in South Carolina; I have
seen no specimens.

2. STEMONITIS TENERRIMA, B. & C. Sporangia small, subcylindric, tapering
and obtuse at the apex, tapering gradually downward, growing close
together on a thin brown hypothallus. Stipe and columella black and
smooth, tapering gradually upward and vanishing toward the apex of the
sporangium, the stipe shorter than the columella. Capillitium of very
slender pale violet threads, which branch and anastomose to form a dense
interior network of large irregular meshes, and then spread out into a
superficial network of small polygonal meshes. Spores globose, even,
pale brownish-violet, 6-8 mic. in diameter. See Plate XI, Fig. 32.

Growing on old wood, mosses, etc. Sporangium with the stipe 5-9 mm. in
height, the sporangium .2-.3 mm. in thickness, the stipe variable in
length, but always shorter than the sporangium. The meshes of the
superficial network varying usually from 3-15 mic. in width, but
sometimes larger from 8-25 mic. The species grows scantily in this
region, but I have elegant specimens from Alabama, sent me by Prof. Geo.
F. Atkinson.

3. STEMONITIS MICROSPORA, Lister. Plasmodium white. Sporangia elongated,
subcylindric, tapering and obtuse at the apex, tapering gradually
downward, growing closely crowded together on a strongly-developed brown
hypothallus. Stipe and columella brown and smooth, tapering gradually
upward and reaching nearly to the apex of the sporangium, the stipe
shorter than the columella. Capillitium of slender tawny-brown threads;
the primary branches simple or only branched above, or with a few
lateral anastomosing branchlets, forming a rather loose network of large
irregular meshes; these support a superficial network of very small
polygonal meshes. Spores globose, even, tawny-brown, 5-6 mic. in
diameter.

Growing on old wood, bark, leaves, etc.; very common in this region.
Sporangium with the stipe 7-15 mm. in height, the sporangium .3-.4 mm.
in thickness, the stipe shorter than the sporangium. Meshes of the
superficial network 4-20 mic. in width. I am indebted to Arthur Lister,
Esq., of London, for pointing out to me the difference between this
species and the _Stemonitis ferruginea_ of Fries and Rostafinski.

4. STEMONITIS FERRUGINEA, Ehr. Plasmodium lemon-yellow. Sporangia
subcylindric, the apex obtuse, growing closely crowded together on a
thin, brown hypothallus. Stipe and columella brown and smooth, tapering
gradually upward and vanishing beneath the apex of the sporangium, the
stipe much shorter than the columella. Capillitium of slender,
tawny-brown threads, which immediately branch and anastomose, forming a
dense interior network of large irregular meshes, supporting a
superficial network of small polygonal meshes. Spores globose, very
minutely warted, tawny-brown in color, 7-9 mic. in diameter.

Growing on old wood, leaves, grasses, etc. Sporangium with the stipe
4-10 mm. in height, the sporangium .3-.4 mm. in thickness, the stipe
much shorter than the sporangium. The meshes of the superficial network
varying from 6-30 mic. or sometimes from 10-40 mic. in width, according
to the specimen. The species is certainly rare in this country, and my
description is drawn up from British specimens. But I am unable to
distinguish authentic specimens of _Stemonitis herbatica_, Peck, from
these British specimens.

§2. MEGALODICTYS. Threads of the capillitium arising from rather distant
points of the columella, branching and anastomosing but a few times,
thus forming an interior network of very large meshes; the superficial
network consisting of large irregular meshes, varying from three or four
to many times the diameter of the spores.

5. STEMONITIS WEBBERI, Rex. Sporangia subcylindric, the apex obtuse,
tapering gradually downward, growing close together on a common
hypothallus. Stipe and columella black and smooth, the stipe very short,
the columella extending nearly or quite to the apex of the sporangium,
the upper part usually flexuous. Capillitium composed of slender,
flexuous brown threads; these immediately branch and anastomose several
times, forming an interior network of very large meshes; the superficial
network consisting of large irregular meshes, sometimes much elongated.
Spores globose, very minutely warted, brown, 7-9 mic. in diameter. See
Plate XI, Fig. 34.

Growing on old wood, bark, etc. Sporangium with the stipe 5-10 mm. in
height, the stipe 1-2 mm. in length, the sporangium .3-.4 mm. in
thickness; meshes of the superficial net of the capillitium 40-100-150
mic. in extent. This is a much smaller species than _Stemonitis
splendens_, and the structure of the interior network of the capillitium
is entirely different.

6. STEMONITIS SPLENDENS, Rost. Sporangia linear-cylindric, obtuse at the
apex, growing close together on a conspicuous hypothallus. Stipe and
columella black and shining, the stipe very short, the columella
reaching nearly or quite to the apex of the sporangium, often flexuous
above. Capillitium composed of brown threads, variable in thickness,
often with membranaceous expansions; the primary branches some of them
simple or only branched above, others with a few anastomosing
branchlets, forming an interior network of extremely large meshes; the
superficial network consisting of large, irregular, roundish or
polygonal meshes. Spores globose, very minutely warted, brown, 7-9 mic.
in diameter. See Plate XI, Fig. 33.

Growing on old wood. Sporangium with the stipe 15-25 mm. in height, the
stipe 4-6 mm. in length, the sporangium about .4 mm. in thickness; the
meshes of the superficial network of the capillitium 25-50-80 mic. or
sometimes as much as 100 mic. in extent. This is _Stemonitis Morgani_,
Peck.


V. ENERTHENEMA, Bowm. Sporangium regular, globose, stipitate; the wall
thin and fragile, fugacious. Stipe stout, thick, tapering upward,
entering the sporangium and prolonged to its apex, there expanding into
a discoid membrane. Capillitium originating from the lower surface of
the apical disk of the columella; the threads branched a few times and
hanging downward, their extremities free. Spores globose, violaceous.

A well-marked genus, by reason of the peculiar origin of the
capillitium.

1. ENERTHENEMA PAPILLATUM, Pers. Sporangium globose, stipitate; the wall
brown or blackish, soon disappearing. Stipe black, rugulose, thick
below, tapering above into the slender columella, which, at its apex,
expands into a thin membranaceous disk. Capillitium of long brown
threads suspended from the apical disk, the threads branched a few
times, occasionally anastomosing by a short, transverse branchlet, the
free ends often forked. Spores globose, very minutely warted,
violaceous, 10-12 mic. in diameter. See Plate XI, Fig. 35.

Growing on old wood. Stipe and columella .8-1.2 mm. in height. The
species seems to be rare in this country, as I have met with it but once
myself, and have received only a few specimens from elsewhere.


VI. DIACHÆA, Fr. Sporangia globose to oblong, stipitate, arising from a
common hypothallus; the wall thin, rugulose, iridescent with metallic
tints, breaking up irregularly and gradually falling away. Stipe and
columella thick, erect, rigid, tapering upward, filled with minute,
roundish granules of lime, white or yellowish in color. Capillitium
arising from numerous points of the columella, the threads repeatedly
branching and anastomosing to form an intricate network, attaining the
wall by numerous short free extremities. Spores globose, violaceous.

This genus is scarcely to be distinguished from Lamproderma, except by
the white mass of lime which fills the tube of the stipe and columella.

1. DIACHÆA LEUCOPODA, Bull. Sporangia ovoid-oblong to short cylindric,
the base obtuse or slightly umbilicate, the apex more rounded; the wall
with bronze, blue, purple, and violet tints, gradually falling away.
Stipe short, thick, white, arising from a white, venulose, hypothallus,
tapering upward; the columella cylindric or slightly tapering, obtuse,
terminating below the apex of the sporangium. Capillitium of slender,
flexuous brown threads forming a dense network of rather small meshes.
Spores globose, very minutely warted, violaceous, 7-9 mic. in diameter.

Growing on old leaves, sticks, etc., and sometimes running over living
plants. Sporangium with the stipe 1-2 mm. in height, the stipe usually
much shorter than the sporangium, the latter .4-.5 mm. in thickness.
_Diachæa elegans_, Fr.

2. DIACHÆA SPLENDENS, Peck. Sporangia globose, sometimes a little
depressed, with the base umbilicate; the wall steel-blue with tints of
purple and violet, quite persistent, rupturing irregularly. Stipe short,
thick, white, arising from a white, reticulate hypothallus, tapering
upward; the columella oblong or short cylindric, extending beyond the
center of the sporangium. Capillitium of slender, brown threads, which
branch several times and form a loose network of rather large meshes.
Spores subglobose, with very large warts, dark violet, 8-10 mic. in
diameter.

Growing on old leaves and twigs. Sporangium .4-.6 mm. in diameter, the
stipe about the same length. This is a beautiful species.

3. DIACHÆA THOMASII, Rex. Sporangia globose, or sometimes a little
depressed; the wall gold-bronze, with tints of purple and blue,
subpersistent, rupturing irregularly. Stipe thick, dull ochre-yellow in
color, variable in length, usually very short and sometimes quite
obsolete, arising from an ochre-yellow hypothallus; the columella
varying from bluntly-conical to cylindric-clavate, attaining the center
of the sporangium. Capillitium of slender, brown threads, radiating from
all points of the columella, branching several times and forming a loose
network of elongated meshes. Spores globose, minutely warted,
violaceous, 11-12 mic. in diameter. See Plate XI, Fig. 36.

Growing on sticks, leaves, etc. Sporangium .5-.7 mm. in diameter, the
stipe usually shorter or sometimes wanting. This species has been found
only in the mountains of North Carolina. I am indebted to Dr. George A.
Rex for my example. In its structure the species is essentially a
Lamproderma, but the stipe and columella are stuffed with granules of
lime.


EXPLANATION OF PLATE XI.

Fig. 25.--Sectional view of the capillitium and stipe of Clastoderma De
Baryanum, Blytt.

Fig. 26.--Section through the capillitium, columella and stipe of
Lamproderma arcyrionema, Rost.

Fig. 27.--Perpendicular section through Lamproderma violaceum, Fr.

Fig. 28.--Perpendicular section through Lamproderma scintillans, Berk.

Fig. 29.--Section through the capillitium, columella and stipe of
Comatricha Ellisii, Morgan.

Fig. 30.--Sectional view through the capillitium and columella of a
portion of Comatricha crypta, Schw.

Fig. 31.--Sectional view through the columella and capillitium of a
portion of Comatricha longa, Peck.

Fig. 32.--A portion of the capillitium of Stemonitis tenerrima, B. &
C.--A sectional view through the columella above and below a view of the
superficial network.

Fig. 33.--A portion of the capillitium of Stemonitis splendens, Rost.--A
sectional view through the columella above and below a view of the
superficial network.

Fig. 34.--The capillitium of a very short sporangium of Stemonitis
Webberi, Rex; the breadth, however, somewhat exaggerated.

Fig. 35.--Showing the stipe, columella, apical disk and pendent
capillitium of Enerthenema papillatum, Pers.

Fig. 36.--Perpendicular section through the capillitium, columella, and
stipe of Diachæa Thomasii, Rex.

NOTE.--The figures of the objects are drawn as they appear under a
magnifying power of about 100 diameters.

[Illustration: The Journal of the Cin. Soc. Natural History.

VOL. XVI.                                        PLATE XI.]




ORDER VII.--DIDYMIACEÆ.


Sporangia simple and subglobose, or plasmodiocarp, rarely combined into
an æthalium. Wall of the sporangium a thin membrane with an outer layer
composed of minute stellate crystals, or of minute roundish granules of
lime; these either lie singly upon the surface, or are compacted into a
crustaceous coat. Stipe present or often wanting; the columella usually
conspicuous and well-developed. Capillitium consisting of very slender,
often sinuous threads, which extend from the base of the sporangium or
from the columella to the walls, either simple or outwardly branching a
few times at a sharp angle, combined into a loose irregular net by a few
transverse branchlets, which are situated chiefly at the extremities.
Spores globose, violaceous.

This order is readily distinguished from the Physaraceæ by the absence
of lime from the threads of the capillitium.

TABLE OF GENERA OF DIDYMIACEÆ.

_a. The lime on the wall of the sporangium in the form of minute
stellate crystals._

1. DIDYMIUM. Sporangium simple, subglobose and stipitate, the base
commonly umbilicate, or sometimes sessile and plasmodiocarp.

2. SPUMARIA. Æthalium composed of numerous elongated
irregularly-branched sporangia, closely compacted together and
confluent.

_b. The lime on the wall of the sporangium consisting of minute roundish
granules._

3. DIDERMA. Wall of the sporangium with the outer calcareous layer
usually compacted into a smooth continuous crust.

4. LEPIDODERMA. Wall of the sporangium with an outer layer of large
scales, consisting of bicarbonate of lime.


I. DIDYMIUM, Schrad. Sporangium simple, subglobose and stipitate, the
base commonly umbilicate, or sometimes sessile and plasmodiocarp; the
wall a thin membrane with an outer layer of minute stellate crystals of
lime. Stipe present or sometimes wanting; the columella mostly
conspicuous, sometimes thin or obsolete. Capillitium of very slender
threads, straight or often sinuous, stretching from the columella to the
wall of the sporangium, simple or outwardly sparingly branched at a
sharp angle. Spores globose, violaceous.

Didymium, together with Spumaria, is to be distinguished from all other
genera of the Myxomycetes by the covering of stellate crystals, like
hoar-frost, upon the outer surface of the sporangium.

§1. CIONIUM. Columella prominent, subcentral, globose, obovoid, or
turbinate; the threads of the capillitium radiating in all directions to
the wall of the sporangium.

_A. Sporangium stipitate._

1. DIDYMIUM SQUAMULOSUM, A. & S. Sporangium variable in form and size,
small and globose, or large and much depressed, the base usually
umbilicate, stipitate, or sometimes sessile, and even plasmodiocarp; the
wall very thin and pellucid, with a thin, gray-white layer of stellate
crystals of lime, breaking up into subpersistent scales. Stipe short,
erect, snow-white, longitudinally furrowed or plicate; the columella
central, snow-white, various in shape, globose, obovoid, turbinate, and
stipitate or sessile. Capillitium of numerous colorless threads,
radiating from the columella and separating outwardly into several
branches. Spores globose, very minutely warted, dark violaceous, 8-10
mic. in diameter.

Growing on old wood, leaves, herbaceous stems, etc. Sporangium .4-.6-.8
mm. in diameter, the stipe scarcely longer than the diameter, often much
shorter or nearly wanting.

2. DIDYMIUM PROXIMUM, B. & C. Sporangium globose or depressed-globose,
the base more or less umbilicate, stipitate; the wall very thin and
pellucid, with a loose white covering of stellate crystals of lime, the
upper part breaking up and falling away. Stipe long, erect, tapering
upward, yellow-brown to reddish-brown, expanding at the base into a
small hypothallus; the columella central, white, turbinate, or discoid
turbinate. Capillitium of slender, colorless threads, radiating from the
columella, branching and often anastomosing. Spores globose, even, pale
violaceous, 8-10 mic. in diameter. Plate XII, Fig. 37.

Growing on old leaves, sticks, culms, etc. Sporangium .4-.6 mm. in
diameter, the stipe two or three times the diameter.

3. DIDYMIUM EXIMIUM, Peck. Sporangium depressed-globose, the base
umbilicate, sometimes very much depressed and also umbilicate above,
stipitate; the wall pale ocher or pale yellow, with a thin layer of
minute white crystals of lime, the upper part gradually breaking away.
Stipe long, erect, tapering upward, pale yellow-brown, darker below,
expanding into a small brown hypothallus; the columella central, large,
discoid, or sometimes rough and irregular, pale ochre or yellowish.
Capillitium of much-branched colorless threads, radiating upward and
downward from the columella. Spores globose, very minutely warted, dark
violaceous, 9-11 mic. in diameter. Plate XII, Fig. 38.

Growing on old leaves, sticks, etc. Sporangium .5-.6 mm. in diameter,
the stipe about twice the diameter.

4. DIDYMIUM MICROCARPUM, Fr. Sporangium small, globose, the base
slightly umbilicate, stipitate; the wall a dark-colored membrane,
covered with abundant snow-white crystals of lime. Stipe long, slender,
erect, delicately striate, yellow-brown to blackish in color, expanded
at the base into a small hypothallus; the columella small, globose,
sessile or substipitate, pale yellow-brown. Capillitium of pale brown
threads, somewhat branched and forming a loose net. Spores globose, very
minutely warted, violaceous, 6-7 mic. in diameter.

Growing on old wood, leaves, mosses, etc. Sporangium .4-.5 mm. in
diameter, the stipe two or three times as long. The species is more
particularly distinguished by its small spores.

5. DIDYMIUM MINUS, Lister. Sporangium depressed-globose, the base
umbilicate, stipitate, rarely sessile and plasmodiocarp; the wall a
dark-colored membrane with a thin layer of stellate crystals of lime,
breaking up gradually and falling away. Stipe erect or sometimes bent at
the apex, variable in length, rarely wanting, from pale brown to
blackish in color, rising from a small hypothallus; the columella
reaching the center, brown or blackish, rough, convex, subglobose or
pulvinate, substipitate. Capillitium of slender colorless threads,
radiating from the columella and more or less branched outwardly. Spores
globose, very minutely warted, violaceous, 8-10 mic. in diameter. Plate
XII, Fig. 39.

Growing in vast abundance in Spring on old leaves, bark, wood, etc.
Sporangium .4-.6 mm. in diameter, the stipe scarcely longer but usually
shorter than the diameter of the sporangium rarely absent. It is
considered by Lister to be a variety of _D. farinaceum_; it differs from
this species in its smaller and less-depressed sporangium and in its
smaller nearly smooth spores.

_B. Sporangia sessile._

6. DIDYMIUM EFFUSUM, Link. Sporangia gregarious or scattered, sessile on
a flattened base, convex above, various in shape, subrotund or by
confluence effused and venosely creeping; the wall very thin and
pellucid, invested with a thin flocculose layer of minute crystals of
lime. The columella hemispheric, rugulose, usually snow-white.
Capillitium of very slender colorless threads, furnished with numerous
minute protuberances, much branched and combined into a dense net.
Spores globose, very minutely warted, dark violaceous, 10-11 mic. in
diameter.

Growing on old leaves, wood, etc. Sporangium about .5 mm. in diameter or
thickness, sometimes confluent and more or less elongated as a
plasmodiocarp. This species is reported from the United States, but I
have seen no specimens.

7. DIDYMIUM PHYSAROIDES, Pers. Sporangia roundish or hemispheric, more
or less irregular and deformed, sessile or with a very short stipe, and
closely crowded together upon a strongly-developed common hypothallus;
the wall a dark colored membrane, with a thin layer of stellate crystals
of lime. The columella large and thick, divided into cells which are
filled with irregular lumps of lime, common to all the sporangia.
Capillitium of stout threads, usually simple, only rarely branched,
furnished with numerous fusiform swellings. Spores globose, minutely
warted, dark violaceous, 12-14 mic. in diameter.

Growing on old wood, bark, moss, etc. Reported from Carolina by Curtis.
It is said superficially to resemble somewhat _Physarum didermoides_.

§2. PLACENTIA. Columella basal, much depressed, very thin or quite
obsolete, connate with the base of the sporangium; the threads of the
capillitium ascending to the wall of the sporangium.

_A. Sporangium stipitate._

8. DIDYMIUM FARINACEUM, Schrad. Sporangium hemispherical, more or less
depressed, the base profoundly umbilicate; the wall firm, rugulose,
dark-colored and nearly opaque, with a mealy coat of stellate crystals
of lime, rupturing irregularly. Stipe variable in length, rigid, erect,
black or sometimes rusty-brown, arising from a small hypothallus; the
columella broad, hemispherical or pulvinate, black, the lower side
connate with the wall of the sporangium. Capillitium of dark-colored
sinuous threads, simple or scarcely branched. Spores globose, dark
violaceous, minutely warted, 10-13 mic. in diameter. Plate XII, Fig. 40.

Growing on old wood, leaves, mosses, etc. Sporangium .6-.9 mm. in
diameter, the stipe about as long as the diameter of the sporangium or
sometimes much longer, usually, however, much shorter than the diameter
and almost concealed within the umbilicus. My specimens are from
Pennsylvania and Alabama. It is readily distinguished from _Didymium
minus_ by the much larger and more distinctly warted spores.

9. DIDYMIUM CLAVUS, A. & S. Sporangium pileate, very much depressed,
convex above and concave below, stipitate; the wall a dark-colored
membrane, thickly covered with minute white crystals of lime, except the
brown concavity underneath, the upper part breaking away, the lower
persistent. Stipe short, erect, rugulose, brown or blackish, expanding
at the base into a small hypothallus; the columella reduced to a thin
layer of minute brown scales upon the base of the sporangium.
Capillitium of simple or sparingly-branched threads, colorless at the
extremities and dark-colored between. Spores globose, even, violaceous,
6-8 mic. in diameter.

Growing on old leaves, sticks, herbaceous stems, etc. The sporangium
.6-.8 mm. in diameter, the stipe about the same length. Fries considered
this to be a mere variety of _D. farinaceum_, but it is readily
distinguished by its very small spores.

_B. Sporangia sessile._

10. DIDYMIUM SERPULA, Fr. Plasmodium yellow. Plasmodiocarp much
depressed, subrotund or usually more or less elongated, bent, flexuous
and reticulate; the wall dark-colored, with a thin layer of stellate
crystals of lime. Columella entirely wanting. Capillitium of very
slender threads, extending from base to upper surface, much branched,
the branches combined into a dense network; to these threads adhere
numerous roundish vesicles, composed of a brownish membrane, inclosing a
yellow coloring matter, the vesicles 30-50 mic. in diameter. Spores
globose, very minutely warted, violaceous, 7-8 mic. in diameter.

Growing on old leaves, bark, etc. The plasmodiocarp .6-.8 mm. in
thickness and extending from one to several millimeters in length. This
species is reported from the United States by Massee. It ought to be
readily recognized by its yellow plasmodium and the peculiar vesicles
adherent to the capillitium.

11. DIDYMIUM ANELLUS, Morgan, n. sp. Plasmodiocarp in small rings or
links, then confluent and elongated, irregularly connected together,
bent and flexuous, resting on a thin venulose hypothallus; the wall
firm, dark-colored, with a thin layer of stellate crystals of lime,
irregularly ruptured. Columella merely a thin layer of brown scales.
Capillitium of slender dark-colored threads, which extend from base to
wall, more or less branched, and combined into a loose net. Spores
globose, very minutely warted, violaceous, 8-9 mic. in diameter. Plate
XII, Fig. 41.

Growing on old leaves in woods in Spring. Plasmodiocarp in rings .3-.5
mm. in diameter, or often more or less elongated into links and chains,
which are bent and flexed in quite an irregular manner, the thread or
vein composing them about .2 mm. in thickness. A more minute species
than _Didymium serpula_, without characteristic thickenings upon the
threads of the capillitium, and wanting the peculiar large cells of this
species.


II. SPUMARIA, Pers. Æthalium composed of numerous elongated,
irregularly-branched sporangia, more or less closely compacted together
and confluent, seated upon a well-developed common hypothallus; the
walls of the sporangia a thin membrane with an outer layer of minute,
stellate crystals of lime. Each sporangium traversed by a central
subcylindric hollow columella, which extends also to the branches, but
does not reach to their apices. Capillitium of slender threads, more or
less branched, and combined into a network. Spores globose, violaceous.

Spumaria is essentially related to Didymium by the crystals of lime upon
the walls of the sporangia. Rostafinski's figure 158 can only be
regarded as ideal or diagrammatic. I am disposed to question the
existence of the central columella altogether; if it does exist, it must
be extremely defective.

1. SPUMARIA ALBA, Bull. Plasmodium white, amplectant. Æthalium variable
in form and size, resting upon a white, membranaceous hypothallus, and
usually covered by a white, friable, common cortex composed of minute
crystals of lime. The component sporangia elongated, irregular, more or
less branched, the branches rude, deformed, compressed, laterally
confluent, obtuse or pointed at the apex; the walls of the sporangia
thin and delicate, rugulose, pellucid, with a tinge of violet,
iridescent when divested of the crystals of lime. Capillitium of slender
threads, more or less branched and combined into a net; the threads dark
colored, with pellucid extremities, and furnished with occasional rings
or roundish swellings throughout their length. Spores globose, densely
spinulose, dark violaceous, 10-14 mic. in diameter. Plate XII, Fig. 43.

Climbing up and surrounding the stems of small shrubs, herbaceous
plants, culms of grasses, etc., especially those of living plants,
rarely effused upon old wood, bark, leaves, etc. The æthalium from two
or three to several centimeters in length, and with a radial thickness
of two or three to several millimeters. The following forms or varieties
have been distinguished as species at different times:

Var. 1. DIDYMIUM. Sporangia irregular, simple or lobed and branched,
lifted up on narrow, flat extensions of the hypothallus, as if furnished
with short white stipes; the common cortex wanting. This is _Didymium
spumarioides_, Fr.; it is probably a dwarf form of the next variety.
Plate XII, Fig. 42.

Var. 2. CORNUTA. Æthalium large and rugged in outline, cinerous from the
scanty cortex; the sporangia loosely compacted, the branches running
out into numerous free-pointed extremities. Capillitium of rather thick
threads, forming a dense net, with broad expansions at the angles.
Spores 11-14 mic. in diameter. This is _Spumaria cornuta_, Schum. It is
evidently the form so elaborately figured by Rostafinski, and which
Fries says abounds in Northern Europe.

Var. 3. MUCILAGO. Æthalium large, even and uniform in outline, covered
by a thick, white, common cortex; the sporangia laterally confluent and
densely compacted together throughout. Capillitium of rather slender
threads, forming a loose net, scarcely expanded at the angles. Spores
10-13 mic. in diameter. This is _Spumaria mucilago_, Nees, as figured by
Greville in the Scottish Cryptogamic Flora. The capillitium is figured
by McBride in The Myxomycetes of Iowa. This is the only form I have met
with in this country.


III. DIDERMA, Pers. Sporangia subglobose and stipitate or more often
sessile, sometimes plasmodiocarp; the wall a thin membrane, with an
outer layer composed of minute roundish granules of lime, which are
usually compacted into a smooth continuous crust. Stipe present or
mostly absent; the columella usually well developed. Capillitium of very
slender threads, stretching from the columella to the wall of the
sporangium, more or less branched, and combined into a loose net by
short lateral branchlets. Spores globose, violaceous.

This genus is easily recognized by the smooth crustaceous layer of lime
on the outer surface of the sporangium; in many cases this easily shells
off or breaks away. Such a coating occurs in a few species of Physarum,
but here the vesicles of lime attached to the threads distinguish them.
This is Chondrioderma of Rostafinski's monograph; the reason for coining
a new name and entirely discarding the old one is not apparent.

§1. LEANGIUM. Sporangium usually stipitate; the wall at maturity
separating from the inner mass of spores and capillitium and splitting
in a stellate manner, the segments becoming reflexed.

1. DIDERMA RADIATUM, Linn. Sporangium depressed-globose, the base
flattened or umbilicate, stipitate or nearly sessile; the wall smooth,
whitish or pale brown, splitting from the apex downward into a few
reflexed irregular segments. Stipe short, thick, erect, tapering
downward, standing on a thin membranaceous hypothallus; the columella
large, convex, globose or obovoid, roughened. Capillitium of slender
dark-colored threads, radiating from the columella, simple or branching
outwardly. Spores globose, minutely warted, dark violaceous, 8-10 mic.
in diameter.

Growing on old bark and wood. Sporangium .8-1.2 mm. in diameter, the
stipe shorter than the diameter, sometimes nearly obsolete. Apparently
rare in this country.

2. DIDERMA FLORIFORME, Bull. Sporangium globose or obovoid, stipitate,
growing closely crowded together on a thin brown membranaceous
hypothallus; the wall smooth, varying in color from whitish or yellowish
to bright brown, splitting into irregular segments, which become
reflexed and revolute. Stipe long, erect, white or yellowish to brown;
the columella elongated, obovoid to clavate, roughened, colored as the
stipe. Capillitium of dark-colored threads, radiating from the columella
and sparingly branched. Spores globose, with minute scattered warts,
dark violaceous, 9-11 mic. in diameter. Plate XII, Fig. 44.

Growing on old wood of oak, hickory, etc., late in Autumn. Sporangium
.7-1.0 mm. in diameter before dehiscence, the stipe usually longer than
the sporangium. The color of stipe, columella and sporangium varies from
white through yellowish to brown; the spores are quite peculiar by
reason of their prominent scattered warts. I do not think _Chondrioderma
Lyallii_, Massee, can be maintained as a separate species.

§2. STROMNIDIUM. Sporangia growing closely crowded together upon a thick
highly-developed calcareous common hypothallus, either seated upon it or
partially imbedded in its substance; the wall rupturing irregularly.

3. DIDERMA SPUMARIOIDES, Fr. Sporangia rather small, irregularly
subglobose, sessile, seated close together on a strongly-developed
whitish or yellowish common hypothallus; the wall white, rugulose,
covered by a dense farinaceous layer of lime. Columella convex,
roughened, white or yellowish, sometimes scarcely developed. Capillitium
rather scanty, of slender colorless threads, sparingly branched,
ascending from the columella. Spores globose, minutely warted,
violaceous, 8-10 mic. in diameter.

Growing on old leaves, bark, moss, etc. Sporangia .4-.6 mm. in diameter,
irregular and rugulose. On account of the pulverulent coat of lime on
the sporangium, Massee refers the species back to Didymium, where it was
placed by Fries.

4. DIDERMA STROMATEUM, Link. Sporangia large, subglobose, depressed,
irregular and angular from mutual pressure, closely crowded together on
a thick yellowish or pinkish common hypothallus; the wall smooth and
even, grayish-white or cinereous, with a thin closely connate outer
layer of minute granules of lime. Columella considerably elevated or
much depressed, convex, subglobose or quite irregular, white or colored,
as the hypothallus, especially at the base. Capillitium of abundant
colored threads, more or less branched and combined into a loose net.
Spores globose, minutely warted, violaceous, 8-10 mic. in diameter.

Growing on Hickory bark. The sporangia .5-.8 mm. in diameter, the
surface smooth. Rostafinski, in his Monograph, places this species as a
variety of _D. spumarioides_, but in the Appendix it is separated as a
species. The sporangia are quite different from those of _D.
spumarioides_, but I can see no difference in the spores.

5. DIDERMA GLOBOSUM, Pers. Sporangia subglobose, more or less irregular
from mutual pressure, closely crowded together on a thick, white
hypothallus, seated upon it or usually sunk into its substance at the
base; the wall with a white, smooth, and polished crustaceous outer
layer of lime, distinct and separable from the inner membrane, easily
breaking into fragments, and falling away: the inner membrane very thin,
rugulose, cinereous with granules of lime or free from them and
iridescent. Columella white, small, irregular, subglobose or
ellipsoidal, rarely wanting. Capillitium of slender, dark colored
threads, more or less branched and combined into a loose net. Spores
globose, very minutely warted, violaceous, 8-10 mic. in diameter.

Growing on old leaves. Sporangia .5-.8 mm. in diameter, the surface
smooth and polished.

6. DIDERMA CRUSTACEUM, Peck. Sporangia subglobose, irregular from mutual
pressure, closely crowded together on a thick, yellowish-white common
hypothallus, and at the base confluent with its substance; the wall with
a creamy white, smooth, crustaceous outer layer of lime, distinct and
separable from the inner membrane, and easily breaking up and falling
away; the inner membrane very thin, rugulose, cinereous and iridescent.
Columella whitish or cream colored, small, irregular, subglobose or
ellipsoidal, often wanting. Capillitium of slender, uneven, dark colored
threads, branched and combined into a loose net. Spores globose,
minutely warted, violet-black, opaque, 12-15 mic. in diameter. Plate
XII, Fig. 45.

Growing on old leaves, sticks, etc. A common species in this country.
Sporangia .7-1.0 mm. in diameter, the surface even but finely
pulverulent rather than polished. _Chondrioderma affine_, Rost., is said
to be the same species. It is readily distinguished from _D. globosum_,
by the much larger spores.

§3. ASTROTIUM. Sporangia gregarious, scattered, or sometimes crowded and
confluent, often much depressed, sessile, rarely stipitate; the
hypothallus none or very scanty.

7. DIDERMA MICHELII, Lib. Sporangia orbicular, very much depressed,
often umbilicate above and concave underneath, stipitate or sessile,
gregarious, with the margins of the sporangia sometimes confluent. The
wall with a white crustaceous layer of lime, which soon ruptures around
the edges, allowing the upper part to break in pieces and fall away; the
inner membrane cinereous, rupturing irregularly. Stipe short, stout,
erect, arising from a small, circular hypothallus, whitish or
alutaceous, longitudinally rugulose, expanding at the apex, the wrinkles
running out as veins on the under side of the sporangium; the columella
much flattened, lenticular or discoid, alutaceous or pinkish.
Capillitium of very slender, colorless threads, simple or forking a time
or two, and connected by short branchlets at the extremities. Spores
globose, even, violaceous, 7-9 mic. in diameter.

Growing on sticks, leaves, herbaceous stems, etc. Sporangium .8-1.2 mm.
in diameter, the stipe shorter than the diameter, sometimes very short
or quite obsolete.

8. DIDERMA TESTACEUM, Schr. Sporangia circular or oval, much depressed,
sessile, without any hypothallus, gregarious, irregularly scattered,
sometimes close and even confluent. The outer calcareous layer of the
wall thick, smooth, crustaceous, separate and distinct from the inner
membrane, white or pinkish-white to rose-red in color, gradually
breaking up in pieces and falling away; the inner membrane thin,
pellucid, cinereous from the adherent granules of lime, irregularly
dehiscent from the apex downward. Columella hemispheric or depressed,
granulose-roughened, white, pinkish, or fleshy-red. Capillitium of very
slender, nearly colorless threads, more or less branched. Spores
globose, very minutely warted, 8-10 mic. in diameter.

Growing on old leaves, wood, mosses, etc. Very common in this country.
Sporangium .6-1.0 mm. in diameter, sometimes a little irregular,
especially the form growing on mosses, and occasionally confluent.

9. DIDERMA CINEREUM, Morgan, n. sp. Sporangia subglobose, more or less
irregular, somewhat depressed, sessile, usually close or crowded,
sometimes confluent; the hypothallus a thin membrane, pellucid or with
occasional patches of lime granules, sometimes not apparent. The wall
very thin, even or rugulose, cinereous, the thin membrane covered by a
single layer of closely-adherent granules of lime, rupturing
irregularly. Columella white, hemispheric or depressed and irregular,
the surface granulose. Capillitium of very slender, colored threads, the
extremities pellucid, more or less branched. Spores globose, minutely
warted, violaceous, 9-11 mic. in diameter. Plate XII, Fig. 46.

Growing on old wood, leaves, etc. The sporangium .3-.5 mm. in diameter,
thin and smooth or rugulose. The species superficially greatly resembles
_Physarum cinereum_.

10. DIDERMA DIFFORME, Pers. Plasmodiocarp roundish, oblong, or more or
less elongated and flexuous, scattered or seriately disposed; the
hypothallus a thin brownish membrane, or commonly not apparent. The
outer calcareous layer of the wall snow-white, thin, smooth, distinct
from the inner membrane, breaking into pieces and falling away; the
inner membrane thin, opaque and bluish or pellucid and iridescent.
Columella reduced to a thin layer of scales and granules upon the
brownish basal membrane. Capillitium scanty, consisting of short nearly
colorless threads, which are simple, or fork a time or two. Spores
globose, even, dark violaceous, 10-13 mic. in diameter.

Growing on bark, leaves, twigs, herbaceous stems, etc. Plasmodiocarp
.3-.5 mm. in thickness and variable in length, sometimes elongated
several millimeters.

11. DIDERMA RETICULATUM, Rost. Plasmodiocarp very much depressed,
roundish, oblong, much elongated and flexuous, closely crowded together
and confluent; the hypothallus a thin white granulose layer of lime,
scarcely broader than the plasmodiocarp. The outer calcareous layer of
the wall white, distinct, very fragile and easily shelling off; the
inner membrane much shrunken and withdrawn from the outer coat,
rugulose, cinereous, with a dense closely-adherent layer of granules of
lime. The columella a thin alutaceous, granulose-roughened layer,
extending along the base of the plasmodiocarp. Capillitium of threads
short and very slender, colorless, somewhat branched. Spores globose,
even, pale violaceous, 6-8 mic. in diameter. Plate XII, Fig. 47.

Growing on old wood, leaves, twigs, etc. Plasmodiocarp .5-.8 mm. in
width, much flattened and usually closely crowded. The rough calcareous
base of the plasmodiocarp might be considered as either all columella or
all hypothallus, with the upper surface leather-colored. I am indebted
to Arthur Lister, of London, for the determination of my specimens.

12. DIDERMA EFFUSUM, Schw. Plasmodiocarp very much flattened,
longitudinally creeping and reticulate or altogether widely effused;
hypothallus none. The wall very thin, smooth, white or cinereous, the
thin membrane covered by a single layer of closely-adherent granules of
lime, rupturing irregularly. The columella reduced to a thin alutaceous
layer of granules of lime, forming the base of the plasmodiocarp.
Capillitium of short colorless threads, extending from base to wall,
the extremities branched and connected together. Spores globose, even,
pale violaceous, 8-10 mic. in diameter. Plate XII, Fig. 48.

Growing on old leaves. The plasmodiocarp forms very much flattened
irregular patches from a few to several millimeters in length or extent.
I am indebted to Dr. Geo. A. Rex, of Philadelphia, for the
identification of my specimens, with those in the herbarium of
Schweinitz, under the name of _Physarum effusum_.


IV. LEPIDODERMA, DeB. Sporangium stipitate or sessile, sometimes
plasmodiocarp; the wall a thin, firm, colorless membrane, with an outer
layer of large scales consisting of bicarbonate of lime, the scales
either lying upon the wall or inclosed in lenticular cavities of the
membrane. Stipe present or absent; the columella usually conspicuous.
Capillitium of very slender threads, simple or outwardly branching at a
sharp angle, connected at the extremities. Spores globose, violaceous.

"In the present genus the carbonate of lime is present in the form of
very minute amorphous lumps until near to maturity, when it is dissolved
and reappears as bicarbonate of lime deposited in comparatively large
flakes."--_Massee._

1. LEPIDODERMA TIGRINUM, Schr. Sporangium large, much depressed,
hemispheric or lenticular, the base umbilicate, stipitate; the wall a
firm, dark colored membrane, variegated with large and small irregular
shining scales, greenish-yellow or straw color, rupturing irregularly.
Stipe stout, thick, erect, rugulose, ochraceous or ferruginous, variable
in length, expanding at the base into a thin hypothallus; the columella
brown, convex or hemispheric. Capillitium of slender, dark colored
threads, simple or sparingly branched, radiating from the columella to
the wall. Spores globose, minutely warted, dark violaceous, 10-13 mic.
in diameter.

Growing on old wood, moss, etc. Sporangium 1-1.5 mm. in diameter, the
stipe 1 mm. or less in length. This appears to be the only species of
the genus thus far discovered in this country.


EXPLANATION OF PLATE XII.

Fig. 37.--Didymium proximum, B. & C. _a._ Sporangium and stipe × 33.
_b._ Section through the columella.

Fig. 38.--Didymium eximium, Peck. _a._ Showing the rough columella of
one form. _b._ Section through the discoid columella of the very much
depressed form. Magnified by 33.

Fig. 39.--Didymium minus, Lister. _a._ Sporangium and stipe × 33. _b._
_c._ _d._ Sections through the columella showing different forms.

Fig. 40.--Didymium farinaceum, Schr. Section through the columella.
After Rostafinski.

Fig. 41.--Didymium anellus, Morgan, _a._ Growing upon a leaf × 3. _b._
Plasmodiocarp × 17.

Fig. 42.--Spumaria alba, Bull. Var. 1. didymium, sporangia × 3. Drawn
from a foreign specimen.

Fig. 43.--Spumaria alba, Bull. _a._ Æthalium natural size. _b._
Capillitium and spores as seen by a magnifying power of 500 diameters.

Fig. 44.--Diderma floriforme, Bull. Stipe and columella × 20.

Fig. 45.--Diderma crustaceum, Peck. _a._ Sporangia crowded on the thick
hypothallus, natural size. _b._ Sporangia × 11. _c._ Section through
outer coat, inner membrane, and columella.

Fig. 46.--Diderma cinereum, Morgan, _a._ Sporangia growing on a leaf ×
3. _b._ Sporangia × 23. _c._ Section through the wall and columella.

Fig. 47.--Diderma reticulatum, Rost. Plasmodiocarp growing on leaf × 3.

Fig. 48.--Diderma effusum, Schw. Plasmodiocarp effused on a leaf × 3.

[Illustration: The Journal of the Cin. Soc. Natural History.

  VOL. XVI.                                       PLATE XII.]

       *       *       *       *       *

Reprint from THE JOURNAL OF THE CINCINNATI SOCIETY OF NATURAL HISTORY,
August, 1896.


THE MYXOMYCETES OF THE MIAMI VALLEY, OHIO.

BY A. P. MORGAN.

Fourth Paper.

(Read May 6, 1896.)




ORDER VIII. PHYSARACEÆ.


Sporangia simple and stipitate or sessile, sometimes plasmodiocarp,
rarely combined into an aethalium; the wall a thin membrane, usually
with an outer layer of minute roundish granules of lime. Stipe present
or often wanting, seldom prolonged within the sporangium as a columella.
Capillitium consisting of slender tubules, which branch repeatedly in
every direction and anastomose to form an intricate network, the
extremities attached on all sides to the wall of the sporangium; the
tubules more or less expanded at the angles of the network and inclosing
minute roundish granules of lime, these granules either aggregated into
nodules with intervening empty spaces or more rarely distributed
throughout their entire length. Spores globose, very rarely ellipsoidal,
violaceous.

This order is at once distinguished from the Didymiaceæ by the presence
of the granules of lime in the capillitium.

TABLE OF GENERA OF PHYSARACEÆ.

I. Tubules of the capillitium having the granules of lime in them
aggregated into roundish or angular nodules, with intervening empty
spaces.

_A. Outer surface of the sporangium destitute of lime._

1. ANGIORIDIUM. Plasmodiocarp laterally compressed, splitting regularly
into two valves.

2. CIENKOWSKIA. Plasmodiocarp terete, elongated, irregularly dehiscent.

3. LEOCARPUS. Sporangia subglobose or obovoid, stipitate or sessile.

_B. Outer surface of the sporangium invested with granules of lime._

_a. Stipe prolonged within the sporangium as a columella._

4. PHYSARELLA. Sporangium oblong, stipitate, the apex re-entrant.

5. CYTIDIUM. Sporangium globose, stipitate, the apex convex.

_b. Stipe never entering the sporangium._

6. CRATERIUM. Sporangium obovoid to cylindric, stipitate.

7. PHYSARUM. Sporangium globose, depressed globose or irregular,
stipitate or sessile.

8. FULIGO. Aethalium a compound plasmodiocarp.

II. Tubules of the capillitium with the granules of lime in them
distributed throughout their entire length.

9. BADHAMIA. Stipe not prolonged within the sporangium as a columella.

10. SCYPHIUM. Stipe entering the sporangium and prolonged within it as a
columella.


I. ANGIORIDIUM, Grev. Plasmodiocarp laterally compressed, more or less
elongated and flexuous, attached by the lower margin to the substratum,
and, at maturity, regularly dehiscent along the upper margin by a
longitudinal fissure; the wall a firm membrane, with the granules of
lime forming a reticulate layer on the inner surface. Capillitium a
loose, irregular net-work of tubules, extending from side to side, and
containing large, irregular nodules of lime. Spores globose, violaceous.

A genus readily distinguished by its laterally compressed plasmodiocarp,
splitting lengthwise by a regular fissure. The wall is a single
membrane, and there is but a single reticulate layer of lime upon it,
which is plainly on the inner surface.

1. ANGIORIDIUM SINUOSUM, Bull. Plasmodiocarp laterally compressed and
very much flattened, more or less elongated and flexuous, sometimes
confluent and branched or reticulate, without any hypothallus; the wall
a more or less thickened and brownish membrane, the inner surface coated
with a dense reticulately thickened white layer of lime, and often
studded with the white nodules. Capillitium of hyaline tubules, forming
a loose irregular net-work, with numerous broad vesicular expansions
filled with lime; the nodules white, very large, irregularly lobed, and
branched. Spores globose, very minutely warted, violaceous, 8-10 mic. in
diameter.

Growing on old leaves, sticks, mosses, etc. Plasmodiocarp commonly about
1 mm. in height and 1-5 mm. in length, but the size is variable. The
color appears to depend upon the thickening of the membrane; when it is
thin and pellucid, the color is white or cinereous from the inner layer
of lime and the contained spores; with a more thickened membrane, the
color becomes ochraceous or brownish. _Physarum bivalve_ Pers. _Physarum
sinuosum_ of Rostafinski's monograph.


II. CIENKOWSKIA, Rost. Plasmodiocarp terete, elongated, flexuous,
creeping, and reticulate, irregularly dehiscent; the wall a more or less
thickened membrane, externally naked, with the granules of lime on the
inner surface. Capillitium of slender tubules, combined into an
irregular network, attached on all sides to the wall of the sporangium,
and bearing everywhere short pointed or uncinate free branchlets; the
lime in thin transverse plates and irregular nodules. Spores globose,
violaceous.

The peculiar characteristic of this genus is the short free hooked and
pointed branchlets of the capillitium.

1. CIENKOWSKIA RETICULATA, A. & S. Plasmodiocarp more or less elongated,
curved and flexuous, simple or branched, sometimes confluent and
reticulate, breaking away first along the upper surface, leaving an
irregular margin. The wall a firm yellow membrane, with thinner hyaline
areas and with thicker yellow-brown or red-brown spots; the outer
surface without any lime, smooth, and shining; the inner surface with a
dense layer of yellow granules raised at intervals into transverse
ridges, these are connected with broad thin flat plates of lime which
traverse the capillitium, forming imperfect septa to the sporangium.
Capillitium consisting of slender yellow tubules, forming a network of
irregular meshes, with slight expansions at the angles and bearing along
the sides short pointed or uncinate free branchlets; the tubules
containing a few scattered yellow nodules of lime various in size and
shape. Spores globose, very minutely warted, violaceous, 8-10 mic. in
diameter.

Growing on old wood, bark, leaves, etc. Plasmodiocarp in veins .3-.5 mm.
in thickness, sometimes forming a net-work a centimeter or more in
extent. This curious Myxomyces seems very rare in America. I have met
with it but once. The specimen in the herbarium of Schweinitz, marked
_Physarum reticulatum_, is not this species, though it answers well
enough to the original description.


III. LEOCARPUS, Link. Sporangia subglobose or obovoid, stipitate or
sessile; the wall a more or less thickened membrane, the external
surface destitute of lime, polished and shining, irregularly dehiscent.
Stipe short, poorly developed or sometimes wanting. Capillitium of
slender tubules, forming an irregular net-work more or less expanded at
the angles; the tubules enlarging at intervals into vesicles, which
usually contain nodules of lime. Spores globose, violaceous.

A genus characterized by the form of the sporangia and the smooth and
glossy surface of the wall.

1. LEOCARPUS PSITTACINUS, Ditm. Sporangium small globose or somewhat
depressed, stipitate or subsessile; the wall a thin membrane, rugulose
and iridescent, with thicker red or yellow spots and patches, destitute
of lime. Stipe weak, erect or inclined, variable in length, the base
expanded, orange to red in color. Capillitium a dense net-work of
tubules, widely expanded at the angles and bearing numerous irregular
vesicles, various in size and form, yellow or orange to red in color.
Spores globose, even, dark violaceous, 7-9 mic. in diameter.

Growing on old wood, leaves, etc. The sporangium .5-.6 mm. in diameter,
the stipe about the same length or sometimes very short. The sporangia
are dull brownish to the naked eye, but when magnified the green,
purple, and blue metallic tints of the wall become apparent. There does
not appear to be any granules of lime either on the wall or in the
capillitium. _Physarum psittacinum_ Ditm.

2. LEOCARPUS CÆSPITOSUS, Schw. Sporangium small subglobose or obovoid to
turbinate, somewhat irregular, stipitate or subsessile; the wall a
reticulately thickened and fragile membrane, yellow-brown to
greenish-yellow or olivaceous in color, externally rugulose and glossy,
the inner surface with scales and patches of lime. Stipe short and
thick, sometimes nearly obsolete, yellowish or reddish brown, darker
below, the base expanded into a small hypothallus. Capillitium a loose
irregular net-work of tubules with wide expansions at the angles; the
nodules of lime large, numerous, white or yellowish, irregular, with
acute angles and pointed lobes. Spores globose, minutely warted, dark
violaceous, 9-11 mic. in diameter.

Growing cæspitosely or scattered on old wood and mosses. Sporangium
.6-.8 mm. in diameter, variable in shape, the stipe usually very short.
_Physarum cæspitosum_ Schw., _North American Fungi_. My specimens, some
of them, have been referred to _Physarum citrinellum_ Peck; others to
_Physarum variabile_ Rex.

3. LEOCARPUS BRUNNEOLUS, Phillips. Sporangium large, globose or somewhat
depressed, sessile; the wall a thick yellow-brown membrane, the outer
surface naked, smooth, and polished, with a dense white inner layer of
granules of lime, dehiscing in a stellate manner, the segments becoming
reflexed. Capillitium of tubules forming a dense net-work, with wide
expansions at the angles; the nodules of lime very large, numerous,
white, angular and irregular. Spores globose, minutely warted, dark
violaceous, 8-10 mic. in diameter.

Growing on bark of oak, California (_Harkness._) Sporangium nearly 1 mm.
in diameter. _Diderma brunneolum_ Phillips. I have taken the description
from Massee's monograph.

4. LEOCARPUS FRAGILIS, Dicks. Sporangium very large, obovoid-oblong,
stipitate or subsessile; the wall a greatly thickened membrane, polished
and shining within and without, from alutaceous or pale umber to
dark-brown in color, destitute of lime. Stipe short, weak, and slender,
arising from a thin hypothallus. Capillitium of slender tubules forming
a loose network of large irregular meshes, with slight expansions at the
angles; the lime white, variable in amount, sometimes quite scanty, then
again filling large portions of the net-work with long-branched and
reticulate masses. Spores subglobose, dark violaceous, opaque, 12-15
mic. in diameter.

Growing gregariously on old wood, leaves, mosses, etc. Sporangium 1.5-2
mm. in length by 1 mm. in thickness, the stipe variable in length, but
usually much shorter than the sporangium. _Diderma vernicosum_ Pers.


IV. PHYSARELLA, Peck. Sporangium oblong, stipitate; the apex re-entrant
and confluent with the hollow columella; the wall a thin membrane
covered with small scales and minute granules of lime, at maturity torn
away at the apex and stellately splitting into a few segments. Stipe
elongated, tapering upward, entering the sporangium and prolonged to the
apex as a tubaeform columella. Capillitium distinguished by two distinct
sets of tubules; the first consisting of long, thick tubules filled with
lime, rising at regular intervals from the wall of the sporangium and
extending to the columella; the second, of very slender threads,
scarcely branched, and nearly destitute of lime, stretching between the
wall and the columella. Spores globose, violaceous.

A genus founded upon the one remarkable species, and more distinct than
any other from the typical genus of the Physaraceae. In fact, the
structure of the sporangium is unique among the Myxomycetes.

1. PHYSARELLA OBLONGA, B. & C. Sporangium oblong, the apex re-entrant
and confluent with the summit of the columella, the base obtuse or
slightly umbilicate, stipitate, cernuous. The wall of the sporangium a
firm, yellowish membrane, covered with minute granules and with
scattered, small, yellow scales of lime; after maturity the apex is torn
away more or less irregularly from the summit of the columella and the
wall splits into a few segments, which become reflexed and are
subpersistent about the base of the sporangium. Stipe long, erect or
flexuous, the apex bent or curved, red-brown, rising from a small
hypothallus, entering the sporangium and prolonged to the apex as a
hollow tubaeform columella. Capillitium of thick, spiniform tubules
filled with lime and slender, violet threads, extending between the wall
and the columella. The tubules elongated, terete, tapering gradually
from wall to columella, containing yellow granules of lime; the threads
very slender, outwardly branched a time or two, the further extremities
connected by short, lateral branches, often furnished with minute, free
branchlets, and containing a few small, fusiform nodules of lime. Spores
globose, nearly smooth, violaceous, 7-9 mic. in diameter.

Growing on old wood, bark, leaves, etc. Sporangium commonly .8-1.0 mm.
in length by .5-.6 mm. in diameter, the stipe 1-2 mm. long; the
spiniform tubules measure 150-200 × 15-20 mic.

The abnormal forms of this species which sometimes manifest themselves
are very singular; the sporangium has a tendency to dilate, becoming
funnel-form or even salver-shaped, the stipe shortening and even
disappearing. I have a large specimen which superficially resembles some
lichen, a _Physcia_, for example; the sporangia are pressed down,
flattened out, extremely irregular, and in many places confluent; the
rudimentary stipes are hidden beneath the leafy expansions. In all the
forms, however, may be uncovered the spiniform tubules mingled with the
slender threads. This is _Trichamphora oblonga_ B. & C. _Tilmadoche
oblonga_ of Rostafinski's monograph, and _Physarella mirabilis_ Peck.


V. CYTIDIUM, Morgan. Gen. nov. Sporangium globose or rarely ellipsoidal,
stipitate; the wall a thin membrane, with an external layer of minute
granules of lime, rupturing irregularly. Stipe more or less elongated,
tapering upward and entering the sporangium as a columella. Capillitium
of slender tubules, arising from the columella, repeatedly branching and
anastomosing to form a regular net-work, the extremities attached on all
sides to the wall of the sporangium, the tubules containing at intervals
nodules of lime. Spores globose, violaceous.

This genus is readily distinguished from _Physarum_ by the columella,
which gives origin to the capillitium; this feature indicates a
relationship to _Didymium_ and to _Lamproderma_.

§1. EUCYTIS. Sporangium globose, the columella not reaching its center.

1. CYTIDIUM PULCHERRIMUM, B. & R. Sporangium globose, stipitate; the
wall a thin lilac-tinted membrane, with a dense closely adherent layer
of granules of lime, dark purple or wine-colored. Stipe long, erect,
dark purple to purplish black, tapering upward and entering the
sporangium as a slight obtuse columella. Capillitium of slender lilac
tinted threads, forming a dense net-work of very small meshes, with
slight expansion at the angles; the nodules of lime very small,
numerous, dark purplish or vinose in color, ellipsoidal or obtusely
angular. Spores globose, even, lilac, 7-9 mic. in diameter.

Growing on old wood. Sporangium .4-.5 mm. in diameter, the stipe two or
three times as long; the lime-nodules about the size of the spores. The
purple stain, which the sporangia leave on white paper, is made by the
granules of lime; the spores color the paper violet. _Physarum
pulcherrimum_ B. & Rav., and _P. atrorubrum_ Peck.

2. CYTIDIUM CITRINUM, Schum. Sporangium globose, the base slightly
flattened or umbilicate, stipitate; the wall a thin membrane, covered
with small scales of lime, yellow or greenish-yellow, breaking up and
falling away at maturity. Stipe stout, erect, yellow, longitudinally
rugulose, expanded at the base, tapering upward and entering the
sporangium as a short obtusely conical columella. Capillitium of slender
tubules, forming a dense net-work, with slight expansions at the angles;
the lime-nodules numerous, roundish or ellipsoidal, variable in size,
yellow. Spores globose, nearly smooth, violaceous, 7-8 mic. in diameter.

Growing on bark, leaves, mosses, etc. Sporangium .5-.6 mm. in diameter,
the stipe from once to twice this length. This, the typical species, I
have not seen in this country, but forms with the sporangium
lemon-yellow and grayish-yellow, with the stipe golden-yellow, connect
it with _C. rufipes_. It is _Physarum citrinum_ Schum. _Diderma
citrinum_ of Fries., S. M.

3. CYTIDIUM RUFIPES, A. & S. Sporangium globose, sometimes a little
depressed and the base umbilicate, stipitate; the wall a thin membrane,
covered with small scales of lime, golden-yellow to orange in color,
breaking up at maturity and falling away. Stipe variable in length,
slender, from orange or orange-red to dark red in color, sometimes
blackish below, rising from a thin hypothallus, tapering upward and
entering the sporangium as a short obtuse columella. Capillitium of
slender tubules, forming a dense net-work of very small meshes, slightly
expanded at the angles; the nodules of lime small, numerous, ellipsoidal
or obtusely angular, orange to red in color. Spores globose, nearly
smooth, violaceous, 8-10 mic. in diameter.

Growing on old wood, mosses, etc. A very abundant species. Sporangium
.5-.7 mm. in diameter, the stipe from once to twice as long. As here
defined, the species includes _Physarum aurantium_ var. _rufipes_ A. &
S., and _Physarum aureum_ var. _chrysopus_ Lev, which I am unable to
keep separate; the variation in size of the spores is not in
correspondence with the variations in color of the sporangia. _Physarum
pulchripes_ Peck, and _Physarum petersii_ B. & C., mostly belong here.
The bright orange colors become dull or tawny with age and exposure to
the weather.

4. CYTIDIUM RAVENELII, B. & C. Sporangium globose, stipitate; the wall a
thin pellucid membrane, covered with small scales of lime, from gray or
drab to pale umber in color, breaking up at maturity and falling away.
Stipe variable in length, concolorous with the sporangium or darker
below, tapering upward and entering the sporangium as a short obtusely
conical columella. Capillitium of tubules, forming a dense net-work of
very small meshes, with slight expansions at the angles; the
lime-nodules small, numerous, ellipsoidal or obtusely angular, gray or
drab to pale umber in color. Spores globose, nearly even, pale
violaceous, 7-9 mic. in diameter.

Growing on old wood, mosses, etc. Sporangium about .5 mm. in diameter,
the stipe once to twice this length. The species as here described
includes _Didymium ravenelii_ B. & C., _Physarum simile_ Rost., and
_Physarum murinum_ Lister.

5. CYTIDIUM GLOBULIFERUM, Bull. Sporangium globose, the base sometimes
flattened or slightly umbilicate, stipitate; the wall a thin, pellucid
membrane, covered with small scales of lime, white, cream-colored, or
sometimes pinkish, breaking up and falling away at maturity. Stipe
variable in length, white or smoky-white, usually darker below, rising
from a thin hypothallus, tapering upward and entering the sporangium as
a short obtuse or conical columella. Capillitium of slender tubules,
forming a dense, persistent net-work of very small meshes, more or less
expanded at the angles; the nodules of lime variable in size, numerous,
white, roundish, ellipsoidal or obtusely angular. Spores globose, nearly
even, pale violaceous, 7-9 mic. in diameter.

Growing on old wood, bark, mosses, etc. A very common and abundant
species. Sporangium .5-.6 mm. in diameter, the stipe from once to two or
three times this length. The lime nodules in the capillitium are
sometimes round and quite minute, then again they are large and obtusely
angular; the columella varies from very short and conical to longer and
more cylindric. _Diderma globuliferum_ of Fries S. M., _Physarum
albicans_ Peck. The specimens with the columella well nigh obsolete, may
be _Tilmadoche columbina_ Rost.

6. CYTIDIUM MELLEUM, B. & Br. Sporangium globose, stipitate or
subsessile; the wall a thin yellowish membrane, rugulose, covered by
large irregular scales of lime, honey-color to golden-yellow, breaking
up irregularly. Stipe short, sometimes very short or nearly obsolete,
snow-white, expanding at the base into a small white hypothallus,
tapering upward and entering the sporangium as a short obtusely conical
columella. Capillitium a loose net-work of delicate tubules with broad
vesicular expansions containing much lime; the nodules numerous, white
or sometimes yellow, large, irregular, lobed, and branched. Spores
globose, nearly even, pale violaceous, 7-9 mic. in diameter.

Growing on old leaves, sticks, herbaceous stems, etc.; not uncommon in
this region. Sporangium .4-.5 mm. in diameter, the stipe about the same
length or much shorter. _Didymium melleum_ B. & Br. _Didymium
chrysopeplum_ B. & C. also belongs here and not with _C. citrinum_.

§2. REXIELLA. Sporangium ellipsoidal or pyriform, the columella
prolonged nearly to the apex of the sporangium.

7. CYTIDIUM PENETRALE, Rex. Sporangium ellipsoidal or pyriform,
stipitate; the wall a thin pellucid membrane, covered with small scales
of lime, yellow-gray to greenish-yellow, rupturing at maturity into two
to four segments. Stipe long, slender, translucent, pale red to dark red
in color, tapering upward, entering the sporangium and prolonged nearly
to the apex as a slender columella. Capillitium of very slender tubules,
radiating from numerous points of the columella, forming a delicate
net-work of very small meshes, scarcely expanded at the angles; the
nodules of lime small, not numerous, roundish or obtusely angled, white
or yellowish. Spores globose, very minutely warted, pale violaceous,
5.5-6.5 mic. in diameter.

Growing on old wood. A rare and singular species. Sporangium .5-.7 mm.
in height by .3-.5 mm. in diameter, the stipe two or three times the
height of the sporangium. There is an affinity between this species and
the _Physarella_. The obscure _Tilmadoche hians_ Rost., may be the same
as the present species.


EXPLANATION OF PLATE XIII.

Fig. 49.--Angioridium sinuosum, Bull. _a._ Plasmodiocarp × 5 _b._
Capillitium and spores × 500.

Fig. 50.--Cienkowskia reticulata, A. & S. _a._ Plasmodiocarp × 5. _b._
Piece of plasmodiocarp × 90. _c._ Capillitium and spores × 500.

Fig. 51. Leocarpus fragilis, Dicks, _a._ Sporangia × 5. _b._ Capillitium
and spores × 500.

Fig. 52.--Leocarpus caespitosus, Schw. _a._ Sporangia × 5. _b._
Capillitium and spores × 500.

Fig. 53.--Physarella oblonga, B. & C. _a._ Sporangia × 5. _b._ Sporangia
× 90. _c._ Capillitium and spores × 500.

Fig 54--Cytidium penetrale, Rex. _a._ Sporangia × 5 _b._ Sporangia and
columella × 90. _c._ Capillitium and spores × 500.

Fig. 55.--Cytidium globuliferum, Bull. _a._ Sporangia × 5. _b._
Sporangia × 90. _c_. Columella × 90 _d._ Capillitium and spores × 500.

[Illustration: The Journal of the Cin. Soc. Natural History.

  VOL. XIX.                                      PLATE XIII.

MORGAN ON MYXOMYCETES]


VI. CRATERIUM, Trent. Sporangium obovoid to cylindric, stipitate; the
upper and usually greater part of the wall covered with granules of
lime, the basal portion naked and more persistent. Stipe short or
sometimes elongated, arising from a small circular hypothallus,
longitudinally plicate, confluent above and similarly colored with the
base of the sporangium. Capillitium of tubules, forming a loose network,
bearing numerous large angular and irregular nodules of lime, which are
often confluent along the axis of the sporangium into a
pseudo-columella. Spores globose, minutely warted, violaceous.

In this genus the sporangium is commonly obovoid, with a naked base
which is confluent with the stipe and similarly colored; after
dehiscence there is left behind the more persistent cyathiform portion
standing on the substratum.

§1. EU-CRATERIUM. Sporangium at maturity dehiscent in a regular
circumscissile manner, the apex falling away as a lid, leaving behind
the more persistent cup-shaped portion.

1. CRATERIUM MINUTUM, Leers. Sporangium cyathiform, stipitate; the lid
slightly convex, discrete from the first, usually depressed below the
rim of the cup, falling away at maturity, and leaving a smooth, circular
margin to the lower cyathiform portion. The wall a thick, firm,
yellow-brown membrane, the outer surface of the cup entirely naked,
smooth and shining, varying greatly in color from alutaceous or
ochraceous to various shades of brown; the lid usually whitened by a
thin layer of granules of lime. Stipe short, erect or bent, and slightly
curved at the apex, varying in color from rusty yellow to reddish brown,
longitudinally plicate, arising from a small, circular hypothallus.
Capillitium of tubules forming a loose net-work, bearing large,
irregular, white nodules of lime, which are sometimes confluent in the
axis of the sporangium. Spores globose, very minutely warted,
violaceous, 8-10 mic. in diameter.

Growing on old wood, sticks, leaves, etc. Sporangium, together with the
stipe, .8-1.4 mm. in height and .3-.5 mm. in diameter, the stipe usually
shorter than the sporangium, sometimes equal to it in length, rarely
longer. The latest authorities include the three species _Craterium
vulgare_, _C. pyriforme_, and _C. minutum_ of Rostafinski's monograph
all in one species.

2. CRATERIUM CONCINNUM, Rex. Sporangium usually minute, broadly
funnel-shaped, stipitate; operculum always more or less convex, rarely
approaching a hemispherical shape, dehiscent in a regular circumscissile
manner. The wall a thick, brownish membrane, externally smooth and
variously colored, sometimes uniformly light or dark umber, sometimes
dark brown below and brownish white above; the operculum brownish white,
darkest in the center. Stipe short, dark brown, longitudinally ridged.
Capillitium of tubules forming a close-meshed net-work, bearing small
rounded or slightly angular nodules of lime, ochre-brown in color.
Spores globose, very minutely warted, brown, 9-10 mic. in diameter.

Growing usually upon chestnut-burs, and frequently associated with
_Lachnobulus globosus_. Sporangium .5-.8 mm. in height including the
stipe and .2-.5 mm. in diameter at the top, the stipe equaling the
sporangium in length. It is readily distinguished by its small nodules
in the capillitium, which are invariably of a dull, brownish-ochre
color.

3. CRATERIUM RUBESCENS, Rex. Sporangium subcylindric or elongated
cyathiform, stipitate; the apex convex, at maturity separating by an
irregular line in a circumscissile manner. The wall dark violet-red,
smooth, except at the upper portion, which is slightly roughened by an
external deposit of scattered lime-granules of a pale, lilac color.
Stipe short, violet-black, wrinkled longitudinally. Capillitium of
tubules forming a loose, irregular net-work, bearing large, violet-red
nodules of lime which are often confluent in the axis of the sporangium.
Spores globose, minutely warted, dark violaceous, 7-9 mic. in diameter.

Growing on old wood, leaves, etc. Sporangium .6-.8 mm. in height
including the stipe and .5-.6 mm. in diameter, the stipe one-half the
height of the sporangium. The species is distinguished by the color,
which exhibits some shade of red or violet-red in every part of its
structure.

4. CRATERIUM MINIMUM, B. & C. Sporangium cylindric or turbinate
cylindric, stipitate; the apex convex, separating in a regular
circumscissile manner by a lid. The wall a thick, yellow-brown
membrane, most of the outer surface covered with minute, white granules
of lime, the basal portion naked. Stipe very short, plicate, red-brown,
arising from a small hypothallus. Capillitium of tubules forming a loose
net-work bearing large, irregular, white nodules of lime, sometimes
confluent in the axis of the sporangium. Spores globose, very minutely
warted, violaceous, 7-9 mic. in diameter.

Growing on old leaves, herbaceous stems, etc. Sporangium together with
the stipe 1-1.5 mm. in height and .25-.35 mm. in thickness, the stipe
.2-.4 mm. in length. This is a common species everywhere in the United
States, and perfectly distinct from _Craterium convivale_. It is
_Craterium cylindricum_ of Massee's monograph, according to Lister.

§2. CUPULARIA, Link. Sporangium irregularly dehiscent, breaking up and
gradually falling away from the apex downward.

_a. Stipe shorter than the sporangium._

5. CRATERIUM CONVIVALE, Batsch. Sporangium obovoid or oblong-obovoid,
stipitate; the wall hyaline, thin and fragile above, the lower portion a
thickened and brownish membrane, the surface, usually most of it,
covered with minute white granules of lime, the base naked and brown.
Stipe very short, erect, red-brown, plicate, arising from a small
hypothallus. Capillitium of tubules forming a dense net-work, bearing
numerous large irregular white nodules of lime, which are often
confluent in the axis of the sporangium. Spores globose, very minutely
warted, violaceous, 8-10 mic. in diameter.

Growing on old leaves, herbaceous stems, etc. Sporangium .6-1.0 mm. in
height including the stipe and .3-.5 mm. in diameter, the stipe much
shorter than the sporangium. The thin apex breaks up into pieces and
falls away, leaving sometimes a regular cyathiform portion, at other
times the margin is broken and irregular. This is _Craterium
leucocephalum_ of Rostafinski's monograph. The specimens of _Physarum
scyphoides_ C. & B. which I have seen appear to be a small form of this
species.

6. CRATERIUM AUREUM, Schum. Sporangium obovoid to oblong obovoid,
stipitate, the wall a thin and delicate membrane above, thicker and
firmer below, hyaline or yellowish, almost entirely covered by a dense
layer of granules of lime, varying from lemon-yellow to orange in color.
Stipe short, erect, yellow to orange, brownish toward the base,
longitudinally plicate, rising from a small hypothallus. Capillitium of
slender tubules, forming a dense net-work, bearing numerous rather small
irregular nodules of lime, yellow or sometimes white in color, and often
confluent along the axis of the sporangium. Spores globose, very
minutely warted, dark violaceous, 8-10 mic. in diameter.

Growing on old leaves, sticks, herbaceous stems, etc. Sporangium and
stipe .7-1.0 mm. in height and .3-.5 mm. in diameter, the stipe .2-.4
mm. long. The elongated form is the common one in this region.
_Craterium mutabile_ Fr.

_b. Stipe longer than the sporangium._

7. CRATERIUM NODULOSUM, C. & B. Sporangium globose or obovoid,
stipitate; the greater part of the wall a thin hyaline membrane, easily
breaking away, covered externally with large white scales and nodules of
lime; the basal portion naked, thickened, and more persistent, red-brown
and plicate. Stipe long, erect or inclined, plicate, red-brown, rising
from a small hypothallus. Capillitium of tubules forming a loose
net-work, containing a variable quantity of lime in the shape of long
irregular white nodules, sometimes confluent, with pointed lobes and
branchlets. Spores globose, very minutely warted, dark violaceous, 10-12
mic. in diameter.

Growing on old wood, bark, leaves, etc. Sporangium .5-.6 mm. in
diameter, the stipe two or three times as long. It is _Badhamia
nodulosa_ C. & B., _Journal of Mycology_, Vol. V, p. 186. Ravenel's
specimens are on _Acacia_ bark. Mr. Webber sent me elegant specimens
from Florida where, he says, it grows commonly on the leaves and bark of
the orange trees.

8. CRATERIUM MAYDIS, Morgan, n. sp. Sporangium globose or obovoid,
stipitate; the upper part of the wall a yellowish membrane, thin and
fragile, covered with large thick scales and nodules of lime,
amber-colored to golden-yellow; the basal portion thicker and more
persistent, naked and plicate, red-brown. Stipe red-brown, long,
slender, plicate, rising from a small hypothallus. Capillitium of thick
tubules, forming a net-work with wide expansions at the angles; the
nodules of lime large, numerous, yellow, angularly lobed and branched.
Spores globose, very minutely warted, pale violaceous, 9-10 mic. in
diameter.

Growing on old stalks of _Zea mays_. Sporangium with the stipe 1-1.5 mm.
in height and .4-.6 mm. in diameter, the stipe always longer than the
sporangium. I find it in abundance on old stalks of Indian corn, but
never on anything else.


VII. PHYSARUM, Pers. Sporangium globose, depressed globose or irregular,
stipitate or sessile; the wall a thin membrane, with an outer layer of
minute roundish granules of lime, irregularly dehiscent. Stipe present
or often wanting, never prolonged within the sporangium as a columella.
Capillitium of slender tubules, forming an intricate net-work, the
extremities attached on all sides to the wall of the sporangium; the
tubules more or less expanded at the angles of the net-work, and
containing at varying intervals nodules of lime. Spores globose,
violaceous.

_Physarum_ is the central genus of the _Physaraceæ_ from which all the
others are detached by characters which for the most part are
unimportant.

§1. LAPIDIUM. Lime in the Capillitium scanty; the nodules small,
roundish, ellipsoidal or fusiform.

_A. Sporangium stipitate._

_a. Sporangia regular._

1. PHYSARUM NUTANS, Pers. Sporangium orbicular, very much depressed, the
base concave or umbilicate, stipitate, cernuous; the wall a thin
pellucid membrane, thickly covered with minute white or yellow roundish
scales of lime, breaking up into irregular fragments, which often remain
attached to the capillitium. Stipe long, slender, tapering upward, bent
or curved at the apex, longitudinally rugulose, brown or blackish at the
base, becoming paler upward and cinereous or whitish at the apex.
Capillitium of very slender threads, rising from the base of the
sporangium, forming a net-work with much elongated meshes, scarcely
expanded at the angles; the nodules of lime white or yellow, ellipsoidal
or fusiform, often very small and few in number, sometimes rather large
and numerous. Spores globose, very minutely warted, violaceous, 8-10
mic. in diameter.

Growing on wood, bark, mosses, etc. A very common species. Sporangium
.4-.5 mm. in diameter, the stipe 1-2 mm. in length, the lime-nodules
commonly not thicker than the spores, but sometimes from once to twice
their diameter. Under this name I have included all the lenticular
species of Persoon's Synopsis, _Physarum nutans_, _P. luteum_, _P.
viride_ and _P. aureum_. There is no difference in these species, except
in the color of the granules of lime; the form of the sporangium and the
shape and color of the stipe are the same in all of them. No two
authorities agree in the presentation of this species.

2. PHYSARUM CUPRIPES, B. & R. Sporangium orbicular, much depressed, the
base umbilicate, stipitate, cernuous; the greater part of the wall thin
and delicate, with a scanty covering of yellow granules of lime,
becoming naked and then brassy and iridescent, after maturity soon
disappearing; the lower basal portion thicker and more persistent, with
a layer of small yellow scales of lime. Stipe long, flexuous, bent at
the apex, plicate, pale brown to yellow-brown, darker toward the base.
Capillitium of slender tubules, forming a dense persistent net-work,
more or less expanded at the angles; the lime-nodules small, numerous,
yellow, angular and fusiform, below often confluent. Spores globose,
very minutely warted, violaceous, 8-10 mic. in diameter.

Growing on old wood; rare. Sporangium .4-.5 mm. in diameter, the stipe
two or three times this length. The lime nodules are found both on the
sides and at the angles of the meshes, and are fusiform or angular
accordingly; the lime is scanty above, but in the lower part of the
capillitium the nodules sometimes run together into lobed and branched
forms. This is _Physarum berkeleyi_ of Rostafinski's monograph.

3. PHYSARUM OBRUSSEUM, B. &. C. Sporangium globose, the base usually
slightly flattened or umbilicate, stipitate and cernuous; the wall a
thin, violaceous membrane, covered by small, roundish, white or yellow
scales of lime, or sometimes naked, splitting irregularly from the apex
downward. Stipe long, slender, tapering upward, flexuous, bent or curved
at the apex, yellow, yellow-brown, or pale brown. Capillitium of very
slender tubules, forming a loose net-work, scarcely expanded at the
angles; the nodules of lime small, white or yellow, roundish or obtusely
angular, few to numerous, rarely wanting. Spores globose, very minutely
warted, violaceous, 8-10 mic. in diameter.

Growing on old wood, bark, mosses, etc Sporangium .2-.4 mm. in diameter,
the stipe 1-2 mm. in length, the lime nodules when abundant once to
twice the diameter of the spores, when scanty very small. This, as I
find it growing, is an extremely variable species; I think its various
forms and appearances cover such species as _Didymium obrusseum_ B. &
C.; _D. tenerrimum_ B. & C.; _Physarum tenerum_ Rex, etc., etc.

4. PHYSARUM NUCLEATUM, Rex. Sporangium globose, stipitate, erect or
slightly nodding; the wall a thin, pellucid membrane, thickly covered
with minute, white, roundish scales of lime, which are exceptionally
sparse or absent, rupturing irregularly. Stipe long, slender,
yellowish-white, longitudinally rugulose, tapering upward, expanded at
the base into a small hypothallus. Capillitium of very slender tubules,
forming a delicate net-work of small meshes, scarcely expanded at the
angles; nodules of lime small, not numerous, roundish, white, usually
concentrated into a large lump in the center of the sporangium. Spores
globose, very minutely warted, violaceous, 6-7 mic. in diameter.

Growing on old wood, bark, etc.; rare. Sporangium .4-.5 mm. in diameter,
the stipe two or three times as long, the lime-nodules about the size of
the spores. The species much resembles some of the forms of _P.
obrusseum_, but is to be distinguished by its central mass of lime and
the small spores.

5. PHYSARUM COMPACTUM, Wingate. Sporangium depressed-globose, the base
slightly umbilicate, stipitate, cernuous; the wall a thin, violaceous
membrane, rugulose and iridescent, studded with large and thick,
snow-white, roundish or elliptic scales of lime, at maturity splitting
from the apex downward into several segments. Stipe long, rather weak,
bent and flexuous, tapering upward, longitudinally rugulose, from
snow-white to whitish-ochre and smoky-white, usually brownish at the
base, and arising from a thin hypothallus. Capillitium a delicate
net-work of very slender threads, with no expansions at the angles; the
lime mostly concentrated in one large, snow-white nodule at the center,
a few very small, roundish nodules scattered through the net-work.
Spores globose, very minutely warted, violaceous, 7-9 mic. in diameter.

Growing on old wood, mosses, etc.; a common species. Sporangium .4-.5
mm. in diameter, the stipe two or three times this length. _Tilmadoche
compacta_ Wingate. It is doubtful if _Tilmadoche columbina_ Rost.
belongs to this species. According to Lister, _Lepidoderma stellatum_
Massee, is the same as this species, and if it be objected to the name
that there is already a _Physarum compactum_ Ehrenberg, it may have to
be called _Physarum stellatum_.

_b. Sporangium more or less irregular_.

6. PHYSARUM LEUCOPHÆUM, Fr. Sporangium globose or depressed-globose,
more or less irregular, the base never umbilicate, stipitate or
subsessile; the wall a thin violaceous membrane, rugulose and
iridescent, with a thin coat of small white scales and granules of lime,
or sometimes nearly naked. Stipe variable in length, sometimes very
short or quite obsolete, occasionally a few of them confluent, wrinkled,
and sulcate, brown below, paler or whitish above. Capillitium a dense
irregular net-work of slender tubules, more or less expanded at the
angles; the nodules of lime white, small, roundish, or angular, few and
scattered. Spores globose, very minutely warted, violaceous, 8-10 mic.
in diameter.

Growing on old wood, bark, leaves, etc. The sporangium .5-.7 mm. in
diameter, the stipe about the same length, or shorter, and sometimes
wanting. The lime on the wall and in the capillitium is never abundant
and sometimes extremely scanty. Rostafinski's presentation of this
species applies well to our specimens.

7. PHYSARUM CONNEXUM, Link. Sporangia subglobose, depressed, more or
less irregular, sometimes confluent, stipitate, or subsessile; the wall
a thin violaceous, or brownish membrane, rugulose, thickly covered with
small white roundish scales of lime, which sometimes accumulate so as to
make the surface rough and uneven. Stipe short, thick, rugulose, from
snow white to smoky or sooty, especially toward the base, sometimes with
a scanty calcareous hypothallus. Capillitium a loose net-work of
tubules, much expanded at the angles; the nodules of lime small, white,
rather numerous, ellipsoidal or fusiform, sometimes confluent and
elongated. Spores irregularly globose, minutely warted, dark violaceous,
9-11 mic. in diameter.

Growing on old wood and bark. Sporangium .6-1.0 mm. in diameter, the
stipe usually shorter than the diameter, sometimes very short; the
lime-nodules about the thickness of the spores. This is a larger and
rougher species than _P. leucophæum_, the sporangium is more often
irregular and the spores darker colored. _P. confluens_ and _P.
connexum_ of Link.

8. PHYSARUM COMPRESSUM, A. & S. Sporangium laterally compressed and much
flattened, subreniform, stipitate or subsessile; the wall a thin
violaceous or brownish membrane, rugulose, thickly covered with small
white roundish nodules of lime, similar to those in the capillitium.
Stipe short, brown or blackish at least below, sometimes pallid or
grayish above, longitudinally rugulose. Capillitium of slender tubules,
forming a loose net-work; the nodules of lime small, white, very
numerous, roundish or ellipsoidal, often confluent end to end. Spores
irregularly globose or angular, minutely warted, dark violaceous, 11-14
mic. in diameter.

Growing on old stalks and leaves of _Zea mays_. Sporangium variable,
.6-1.0 mm. in breadth, the stipe 1 mm. or less in length; the lime
nodules about the thickness of the spores. According to Saccardo this
species is the same as _Physarum nephroedium_ Rost.

9. PHYSARUM POLYCEPHALUM, Schw. Sporangia confluent into a subspheric
gyrose-complicate head, composed of several to many laterally
compressed, irregular, simple sporangia; the wall a thin, pellucid
membrane, covered by a thin layer of minute scales of lime, white to
yellow or greenish-yellow Stripes thin, flat, weak, and often prostrate,
pale yellow, more or less connate, arising from a thin hypothallus.
Capillitium of slender tubules forming a loose, irregular network, more
or less expanded at the angles: the lime-nodules white or yellow, small,
fusiform or by confluence elongated and sometimes branched. Spores
globose, very minutely warted, violaceous, 8-10 mic. in diameter.

Growing on old bark, wood, leaves, etc. The sporangia rarely simple,
usually confluent into a head of from four or five to fifteen or twenty,
and sometimes more, simple sporangia; the stipes variable in length,
long or short, rarely wanting. The gray form is _Didymium polymorphum_
Mont., the yellow-green form _D. gyrocephalum_ Mont. Sprengel considered
this species the same as _Physarum compactum_ Ehr., and it appears under
this name in Schweinitz's _North American Fungi_; but Fries, who had
seen specimens of both, disposed of them differently.

10. PHYSARUM DIDERMOIDES, Pers. Sporangia obovoid-oblong, stipitate,
growing close together on a white membranaceous common hypothallus; the
wall with a thick, white, outer layer of lime, easily crumbling and
falling away, leaving the sporangium dark gray; the inner membrane
rather thick and firm, violaceous, with a closely adherent layer of
granules of lime. Stipes very short, white, thin, and weak, each formed
by a bit of membrane arising from the hypothallus. Capillitium a loose
net-work of slender threads, bearing numerous roundish or irregular
white nodules of lime. Spores irregularly or angularly globose, minutely
warted, dark violaceous, 12-15 mic. in diameter.

Growing on wood, leaves, grass, etc. Sporangia .6-1.2 mm. in length by
.4-.6 mm. in thickness, the stipe shorter than the sporangia. _Spumaria
licheniformis_ Schw., belongs here. This is a truly abnormal species of
_Physarum_, so much so that Fries, in the _Summa Veg. Scand._ placed it
by itself in a separate genus, _Claustria_.

_B. Sporangia sessile._

11. PHYSARUM CONFLUENS, Pers. Plasmodiocarp roundish, oblong or
elongated, and by confluence branched and reticulate; the wall a thin,
violaceous membrane, rugulose, with a thin, closely adherent layer of
minute granules of lime, over which are scattered small, white, roundish
nodules, which sometimes accumulate into a thick, pulverulent coat.
Capillitium a loose net-work of tubules, widely expanded at the angles;
the nodules of lime small, white, very numerous, roundish or
ellipsoidal, by confluence elongated and irregular. Spores irregularly
globose, minutely warted, dark violaceous, 9-11 mic. in diameter.

Growing on old wood, bark, leaves, etc. Plasmodiocarp .4-.5 mm. in
thickness, varying from roundish to much elongated, creeping and
reticulate. The sporangium before dehiscence is gray, whence Link's
name, _Physarum griseum_; the loose pulverulent coating of lime easily
falls away, leaving the sporangium dark colored, whence Rostafinski's
name, _Physarum lividum_. The amount of lime on the wall and in the
capillitium is variable.

12. PHYSARUM LUTEOLUM, Peck. Sporangia small, subglobose, sessile,
closely gregarious; the wall a thin membrane, covered by a layer of
small scales of lime, yellowish, inclining to tawny, in color, rupturing
irregularly. Capillitium of slender tubules, forming a dense net-work of
small meshes, scarcely expanded at the angles; the nodules of lime
small, numerous, yellowish, roundish, or ellipsoidal. Spores globose,
nearly smooth, violaceous, about 10 mic. in diameter.

Growing on living leaves of _Cornus canadensis_, Adirondack Mountains,
New York. I have not seen a specimen of this _Physarum_, but from
Professor Peck's description and figure it seems to be a unique species.

13. PHYSARUM THEJOTEUM, Fr. Sporangia very small, sessile, on a thin
membranaceous hypothallus, closely crowded together and more or less
connate, subobovoid or oblong, irregular from mutual pressure; the wall
a thin violaceous membrane, closely covered with a thin layer of small
irregular scales of lime, tawny or yellowish tawny in color, breaking up
irregularly about the apex. Capillitium a loose irregular net-work of
slender threads, more or less expanded at the angles; the lime nodules
small, tawny or yellowish, not numerous, ellipsoidal or fusiform, by
confluence elongated and irregular. Spores globose, even, violaceous,
6-7 mic. in diameter.

Growing on old wood, mosses, etc. Sporangia .2-.4 mm. in diameter at the
apex, densely packed and their walls grown together, approaching the
aethalioid structure; the lime-nodules from one to two or three times
the diameter of the spores in thickness. I have described my specimens,
which are abundant, very carefully, and judge them to be referable to
this species; if so, they show that the species should be kept apart
from _Physarum virescens_. _Didymium nectriæforme_ B. & C., is evidently
this same species.

14. PHYSARUM LATERITIUM, B. & R. Sporangia sessile, irregularly globose
and gregarious, or by confluence more or less elongated and
plasmodiocarp; the wall a thin violaceous membrane, rugulose and
iridescent, closely covered with small irregular scales of lime, from
testaceous or brick-red to bright red in color. Capillitium a dense
irregular net-work of tubules, much expanded at the angles; the nodules
of lime small, very numerous, roundish or angular, whitish or yellowish,
sometimes tinged with red granules. Spores globose, very minutely
warted, violaceous, 8-10 mic. in diameter.

Growing on old wood, sticks, leaves, etc. Sporangia .4-.6 mm. in
diameter, by confluence sometimes much elongated; the lime-nodules two
or three times the diameter of the spores in thickness. _Didymium
lateritium_ B. & R. _Physarum inequale_ Peck, is the same species.

§2. SAXELLA. Lime in the capillitium abundant, the nodules large,
angular or irregular, with pointed lobes and branchlets.

_A. Sporangia stipitate._

15. PHYSARUM IMITANS, Racib. Sporangium depressed-globose, the base
flattened or umbilicate, stipitate, erect or cernuous; the wall a thin
violaceous membrane, with a closely adherent layer of minute granules,
over which are scattered rather large, roundish or irregular white
scales of lime, splitting from the apex downward into a few irregular
segments. Stipe short, thick at the base and tapering upward,
longitudinally rugulose, from gray to brown or blackish, especially
below. Capillitium a loose irregular network of tubules, widely expanded
at the angles; the nodules of lime white, numerous, large, irregular,
with pointed angles and lobes. Spores globose, very minutely warted,
violaceous, 8-9 mic. in diameter.

Growing on old wood, mosses, etc. Sporangium .4-.5 mm. in diameter, the
stipe about the same length or a little longer. The species
superficially resembles the gray form of _Physarum nutans_, and quite
likely is constantly overlooked on this account. Although I am not able
to verify my reference, yet my specimens answer so well to the
description of Raciborski that I am unwilling to invent a new name.

16. PHYSARUM ORNATUM, Peck. Sporangium globose or depressed-globose,
stipitate; the wall a thin yellowish membrane, covered with minute
granules and small irregular scales of lime, yellow to orange in color.
Stipe short, erect, blackish-brown, black at the base, longitudinally
plicate, rising from a small hypothallus. Capillitium of tubules forming
a rather dense net-work, with wide expansions at the angles; the nodules
of lime large, numerous, yellow, irregular, sometimes confluently
branched and reticulate. Spores globose, minutely warted, dark
violaceous, 10-12 mic. in diameter.

Growing on old wood, bark, mosses, etc. Sporangium about .5 mm. in
diameter, the stipe about the same length or shorter. _Physarum oblatum_
McBride, can not be distinguished from this. Specimens of this species
in the herbarium of Schweinitz are labeled _Physarum sulphureum_; this
is without doubt a mistake.

17. PHYSARUM GRAVIDUM, Morgan, n. sp. Sporangium depressed-globose, the
base umbilicate, stipitate; the wall a thin, violaceous membrane,
brownish at the base, with a thin coat of small, white scales and minute
granules of lime. Stipe long, erect, brown or reddish-brown, darker
below, tapering upward, expanding at the base into a small hypothallus.
Capillitium of slender tubules forming a loose net-work, more or less
expanded at the angles and for the most part filled with lime; the
nodules white, slender, much elongated and branched, with pointed lobes
and branchlets. Spores globose, very minutely warted, dark violaceous,
11-13 mic. in diameter.

Growing on old stalks of _Zea mays_. Sporangium .5-.6 mm. in diameter,
the stipe about twice this length. The lower part of the capillitium is
sometimes entirely filled with lime, so that the species approaches
Badhamia in the structure of its capillitium.

18. PHYSARUM LEUCOPUS, Link. Sporangium globose, the base slightly
flattened, stipitate; the wall a thin, violaceous membrane, with a
white, pulverulent outer coat of minute granules of lime. Stipe short,
thick, erect, snow-white, longitudinally rugulose, tapering upward,
expanding at the base into small, white hypothallus. Capillitium a loose
net-work of tubules, with wide expansions at the angles; the nodules of
lime large, white, numerous, irregularly lobed and branched. Spores
globose, very minutely warted, violaceous, 8-10 mic. in diameter.

Growing on old wood, leaves, etc. Sporangium .3-.4 mm. in diameter, the
stipe about the same length as the diameter. Our specimens are a smaller
form than the European, with smaller and smoother spores. Superficially
the species resembles _Didymium squamulosum_, and it is _Didymium
leucopus_ of Fries, S. M.

19. PHYSARUM GLAUCUM, Phillips. Sporangium globose, or the base slightly
depressed, stipitate; the wall a thin, violaceous membrane, covered with
minute, white granules and small roundish or irregular scales of lime.
Stipe short, stout, erect, black, longitudinally wrinkled, expanding at
the base into a small hypothallus. Capillitium of much-flattened
tubules, forming a loose net-work, widely expanded at the angles; the
nodules of lime numerous, large, white, irregular, with pointed angles
and lobes. Spores globose, very minutely warted, dark violaceous, 12-14
mic. in diameter.

Growing on old leaves: California. Sporangium .5-.7 mm. in diameter,
the stipe not longer than the diameter. This is quite a robust species,
both externally and in the broad, flat tubules of the capillitium.

20. PHYSARUM RELATUM, Morgan, n. sp. Sporangium globose, the base
umbilicate, stipitate, often cernuous; the wall a thin, violaceous
membrane, rugulose and iridescent, covered with small, roundish or
irregular white scales of lime. Stipe long, erect or inclined, rising
from a thin hypothallus, tapering upward, white or cream color to
ochraceous. Capillitium a dense net-work of tubules, more or less
expanded at the angles, and almost entirely filled with white granules
of lime, leaving only here and there short, slender empty spaces. Spores
globose, nearly smooth, violaceous, 8-9 mic. in diameter.

Growing on old wood. Sporangium .5-.6 mm. in diameter, the stipe about
twice this length. The capillitium is rigid, with the abundance of lime
almost as in the genus _Badhamia_. Superficially the species much
resembles _Cytidium globuliferum_ or _Physarum compactum_, but the
disposition of the lime on the wall and in the capillitium is altogether
different.

21. PHYSARUM AURISCALPIUM, Cke. Sporangia subglobose, depressed,
substipitate; the wall a hyaline membrane with a thin, closely adherent
layer of minute granules of lime, over which are scattered large,
irregular, orange-red scales of lime. Stipe very short, sometimes almost
obsolete. Capillitium of tubules forming a loose net-work, with widely
expanded angles, and mostly filled with orange granules of lime, only
here and there short, slender, empty spaces. Spores globose, minutely
warted, dark violaceous, 11-13 mic. in diameter.

Growing on rotten wood; South Carolina, Ravenel. Sporangia .6-.8 mm. in
diameter, the stipe very short. Described in _Annals of the Lyceum of
Natural History of New York_, June, 1877. So fine a species ought to be
found again. Cooke's specimen was examined by Lister, _Mycetozoa_, p.
61.


EXPLANATION OF PLATE XIV.

Fig. 56.--Craterium minimum, B. & C. _a._ Sporangia × 5. _b._ Sporangium
with lid × 90. _c._ Capillitium and spores × 500.

Fig. 57.--Craterium maydis, Morgan. _a._ Sporangia × 5. _b._ Sporangium
× 90. _c._ Capillitium and spores × 500.

Fig. 58.--Physarum obrusseum, B. & C. _a._ Sporangia × 5. _b._
Sporangium × 90. _c._ Capillitium and spores × 500.

Fig. 59.--Physarum connexum, Link. _a._ Sporangia × 5. _b._ Sporangium ×
90. _c._ Capillitium and spores × 500.

Fig. 60.--Physarum polycephalum, Schw. _a._ Sporangia × 5. _b._
Sporangia × 90. _c._ Capillitium and spores × 500.

Fig. 61.--Physarum lateritium, B. & C. _a._ Sporangia × 5. _b._
Sporangia × 90. _c._ Capillitium and spores × 500.

Fig. 62.--Physarum imitans, Racib. _a._ Sporangia × 5. _b._ Sporangium ×
90. _c._ Capillitium and spores × 500.

Fig. 63.--Physarum relatum, Morgan. _a._ Sporangia × 5. _b._ Sporangia ×
90. One divested of the wall and showing the rigid capillitium. _c._
Capillitium and spores × 500.

[Illustration: The Journal of the Cin. Soc. Natural History.

  VOL. XIX.                                       PLATE XIV.

MORGAN ON MYXOMYCETES.]

_B. Sporangia sessile._

22. PHYSARUM PLUMBEUM, Fr. Sporangia small, globose or obovoid, sessile,
on a narrow base, gregarious, sometimes close but seldom confluent; the
wall a thin violaceous membrane, with a very thin layer of small white
scales and minute granules of lime, sometimes naked. Capillitium a loose
net-work of slender tubules, with slight expansions at the angles; the
nodules of lime white, numerous, more or less elongated, irregularly
lobed and branched. Spores globose, even, violaceous, 7-9 mic. in
diameter.

Growing on old leaves, sticks, etc. Sporangia .3-.4 mm. in diameter,
quite regular in shape, attached by a narrow base, sometimes by a mere
point, rarely confluent. The lime on the wall of the sporangium is
rather scanty, sometimes altogether absent, and the nodules of lime in
the capillitium are rather small. The species is figured by Micheli N.
P. G. Tab. 96, Fig. 9. It is named by Fries S. M., III, p. 142. It is
figured again by De Bary, _Die Mycetozoen_, Tafel I.

23. PHYSARUM ATRUM, Schw. Sporangia sessile, subglobose or oblong, by
confluence, more or less elongated, bent or flexuous and branched; the
wall a thin violaceous membrane, rugulose, covered by a wrinkled and
reticulate layer of white granules of lime, which sometimes become thin
or disappear. Capillitium a loose net-work of tubules, more or less
expanded at the angles; the nodules of lime white, numerous, large,
irregularly lobed and branched. Spores globose, very minutely warted,
violaceous, 8-10 mic. in diameter.

Growing on old leaves, bark, grasses, etc.; apparently the most common
of these three cinereous species. Sporangia .3-.5 mm. in thickness, some
of them roundish or oblong, others elongated to several millimeters. The
sporangium is often elegantly reticulate as observed by Schweinitz even
when the lime is quite scanty. In Saccardo's _Sylloge_ Berlese changed
the name to _Physarum reticulatum_, but this is unnecessary, as the
_Physarum atrum_ of Fries is not a Myxomyces.

24. PHYSARUM CINEREUM, Batsch. Sporangia large, subglobose, sessile,
gregarious, sometimes close and confluent; the wall a thin violaceous
membrane, with a closely adherent layer of minute granules, over which
are scattered irregular white scales of lime. Capillitium of tubules
forming a loose net-work, with wide expansions at the angles; the
nodules of lime numerous, white, very large, with pointed angles and
lobes, by confluence often branched and reticulate, and occasionally
forming a pseudo-columella in the center of the sporangium. Spores
globose, minutely warted, dark violaceous, 10-13 mic. in diameter.

Growing on old wood, leaves, etc. The sporangia .4-.6 mm. in diameter,
more or less irregular. The great abundance of lime in the capillitium
and the large distinctly warted spores distinguish this species.
_Physarum cinereum_ of Persoon's Synopsis, _Didymium cinereum_ of Fries'
_Systema_. The only American specimens I have of this species are from
Iowa (_McBride_) and from Nebraska (_Webber_).

25. PHYSARUM VIRESCENS Ditm. Sporangia large, subglobose, irregular and
unequal, sessile, gregarious, sometimes crowded, but not often
confluent; the wall a thin membrane, violaceous, or in places yellowish,
with a dense layer of yellow or greenish-yellow scales and granules of
lime. Capillitium a loose net-work of tubules, with wide expansions at
the angles; the nodules of lime large, numerous, yellow or
greenish-yellow, more or less elongated, lobed, and branched. Spores
globose or somewhat irregular, very minutely warted, violaceous, 9-11
mic. in diameter.

Growing on old leaves, mosses, etc. Sporangia .5-.8 mm. in diameter,
occasionally by confluence more elongated. Though found in all parts of
the country, the species seems rare. This is not the _Physarum
virescens_ described by Rostafinski.

26. PHYSARUM RUBIGINOSUM, Fr. Sporangia subglobose, sessile, gregarious;
the wall a thin hyaline membrane, thickly covered with large irregular
scales of lime, orange to red or dark red in color, breaking up
irregularly. Capillitium of hyaline tubules, forming a loose irregular
net-work, more or less expanded at the angles; the nodules of lime
large, angular, and irregular, sometimes confluent, orange to dark red
in color. Spores globose, very minutely warted, dark violaceous, 9-11
mic. in diameter.

Growing on old wood, leaves, mosses, etc. Sporangia .6-.8 mm. in
diameter. _Physarum fulvum_ Fries S. M., III, p. 143. A rare species. It
should not be confounded with _Physarum lateritium_.

27. PHYSARUM SERPULA Morgan, _n. nom._ Plasmodiocarp roundish or oblong
to much elongated, bent, annular and flexuous, sometimes by confluence
branched and reticulate; the wall a firm yellowish membrane, with a
thin, rough, closely adherent coat of granules of lime, dull ochre to
lemon-yellow and orange in color. Capillitium a dense net-work of
tubules, for the most part filled with lime, only here and there short,
slender, empty spaces; the nodules large, numerous, white or yellow,
angular and with pointed lobes and branchlets. Spores globose, minutely
warted, dark violaceous, 9-11 mic. in diameter.

Growing on leaves, bark, lichens, etc. Plasmodiocarp .3-.4 mm. in
thickness and of varying length. This species is in the herbarium of
Schweinitz, at Philadelphia, with the name _Physarum reticulatum_; it is
described by George Massee as _Physarum gyrosum_; by Lister it is
incorporated with several other species under _Badhamia decipiens_.

28. PHYSARUM CONTEXTUM, Pers. Sporangia sessile and closely crowded
together, roundish or more or less elongated, flexuous and complicate,
the apex plane or impressed; the wall a firm yellowish membrane, covered
by a thick pulveraceous layer of lime, white, ochraceous or yellow,
easily crumbling and breaking up. Capillitium a loose net-work of
tubules, much expanded at the angles; the nodules of lime very large,
white or yellow, numerous, angular, and irregular, by confluence lobed
and branched, sometimes massed together in the center of the sporangium.
Spores globose, minutely warted, dark violaceous, 10-13 mic. in
diameter.

Growing on bark, leaves, mosses, etc. Sporangia with a width of .3-.5
mm. and varying in length from .5 mm. to 1 or 2 mm. The sporangia are
often so much crowded as to appear to be grown together. _Diderma
ochroleucum_ B. & C. belongs to this species. _Physarum conglomeratum_
Fr. is a closely related species, with smaller and smoother spores. I
have not met with this.

29. PHYSARUM DIDERMA, Rost. Sporangia large, irregularly globose or
oblong, sessile, but without a hypothallus, closely crowded together and
sometimes confluent. The wall composed of two distinct and separate
layers; the outer a thick, uneven, crustaceous, snow-white layer of
lime; the inner a thin, violaceous membrane, cinereous from the adherent
granules of lime, or free from them, and iridescent. Capillitium of
tubules forming a loose net-work, with wide expansions at the angles;
the nodules of lime numerous, snow-white, large, irregular, with pointed
angles and lobes, sometimes confluent in the center of the sporangium.
Spores globose, minutely warted, dark violaceous, 9-10 mic. in diameter.

Growing on wood, bark, and mosses. Sporangia .8-1.0 mm. in diameter,
more or less irregular. The wall of the sporangium is exactly like that
of certain species of _Diderma_. This species must be rare, as I have
met with it but twice in ten years, and I am not aware that it has ever
been found by any one else.


VIII. FULIGO, Haller. Aethalium a compound plasmodiocarp; the component
sporangia branching and anastomosing in every direction, complicate and
grown together; the walls of the sporangia a thin membrane, coated with
minute, roundish granules of lime. Capillitium of tubules forming a
net-work of irregular meshes, more or less expanded at the angles, the
tubules containing in greater or less abundance irregular nodules of
lime. Spores globose or sometimes ellipsoidal, violaceous.

The genus is readily distinguished from _Spumaria_ by the round granules
of lime upon the walls of the sporangia.

§1. AETHALIUM, Link. Aethalia large; the lime in the capillitium scanty,
the nodules small, ellipsoidal, or fusiform.

_a. Aethalium with a thick fragile common cortex._

1. FULIGO RUFA, Pers. Plasmodium a large soft mass with a peculiar odor
and golden yellow in color. Aethalium very large, pulvinate, orbicular,
elongated, or quite irregular, extremely friable, the surface tawny or
ferruginous to ochraceous and whitish. The long narrow, sinuous
sporangia closely compacted, entirely grown together and inseparable,
covered by a thick common cortex, and seated on a much thickened
hypothallus; walls of the sporangia a thin pellucid membrane, coated by
a thin layer of white granules of lime. Capillitium of very slender
tubules, extending across from wall to wall, sparingly branched and
scarcely forming a network, not at all or only slightly expanded at the
angles; the tubules for the most part empty, here and there with slight
fusiform or elongated swellings containing granules of lime,
occasionally bearing roundish or ellipsoidal nodules of larger size.
Spores globose, nearly smooth, violaceous, 6-9 mic. in diameter.

Growing on old trunks in woods in great abundance from early Spring to
Winter. Aethalium 3-6 or sometimes many centimeters in extent and 1-2
cm. in thickness. The common cortex and the hypothallus are a millimeter
or more in thickness; they are composed of successive layers of thin
plates of membrane coated with granules of lime.

_b. Aethalium naked, i. e., without a common cortex._

2. FULIGO VIOLACEA, Pers. Plasmodium a soft effused mass, dark red or
wine-colored. Aethalium large, pulvinate or effused, orbicular or more
or less elongated and irregular, the surface minutely pitted and
perforate, furnished with a scanty layer of lime, whitish or yellowish
to brick-red in color, leaving naked purple and violet spots and
patches, seated on a thin membranaceous brick-red hypothallus. Sporangia
long, narrow, and sinuous, closely packed together; the walls a thin
violaceous membrane, rugulose and iridescent, with scattered granules,
or nearly destitute of lime. Capillitium of slender violet tubules,
forming a loose net-work, with slight expansions at the angles; the
tubules with numerous rather large vesicular expansions, ellipsoid or
fusiform in shape, and scantily furnished with lime. Spores globose,
nearly smooth, pale vinous, 6-8 mic. in diameter.

Growing on old trunks in woods; not uncommon in this region. Aethalium
1-3 or more centimeters in extent, and 5-10 mm. in thickness. The
vesicles of the capillitium vary from 15-30 or sometimes to 50 mic. in
diameter, their inner surface is usually coated by a single layer of
granules of lime, they are rarely filled with lime and sometimes are
naked entirely; when dry many of them are to be found collapsed.

3. FULIGO FLAVA, Pers. Plasmodium effused lemon-yellow. Aethalium mostly
effused, irregular, the surface reticulate, pitted and perforate,
entirely naked, pale yellow to lemon-yellow and greenish-yellow, the
hypothallus thin or scarcely evident. Sporangia laterally much
compressed, flexuous, and gyrose, not everywhere grown together, but
forming a dense reticulum; the walls a thin, pellucid membrane, with a
dense layer of lemon-yellow granules of lime. Capillitium of short and
very slender tubules, sparingly branched and scarcely forming a
net-work, not expanded at the angles; the tubules very scantily
furnished with lime, in scattered, small, fusiform nodules, white or
lemon-yellow. Spores globose, very minutely warted, violaceous, 7-9 mic.
in diameter.

Growing on mosses, old leaves, sticks, etc.; not common. Aethalia in
irregular patches 2-4 cm. or more in extent, sometimes almost reduced to
a simple plasmodiocarp. This species furnishes a clear notion of the
structure of the aethalium in the other species, on account of the
sporangia being but loosely compacted and not entirely grown together.
The _Fuligo vaporaria_ Pers., of the green-houses and gardens I have
never seen; the _Mucor septicus_ Linn., was thought to be the plasmodium
of this. Linnæus's description is simply "_Mucor unctuosus flavus._"

§2. AETHALIOPSIS, Zopf. Aethalium small; lime abundant in the
capillitium, the nodules numerous and large, angular and irregular.

4. FULIGO MUSCORUM, A. & S. Plasmodium effused, golden yellow. Aethalium
small, subpulvinate, irregular, the surface furnished with scattered,
irregular scales of lime, whitish or ochraceous to golden yellow in
color, arising from a thin, white, membranaceous hypothallus. Sporangia
closely packed and grown together; the walls a thin, violaceous
membrane, rugulose, with a thin, closely adherent layer of granules of
lime. Capillitium a loose net-work of tubules, widely expanded at the
angles; the tubules for the most part filled with lime, the nodules
white or yellowish, numerous, very large, angular and irregular,
sometimes confluent with pointed lobes and branchlets. Spores
irregularly globose, minutely warted, dark violaceous, 9-11 mic. in
diameter.

Growing on leaves, twigs, mosses, etc. Aethalium from 2 or 3 mm. to a
centimeter or more in extent. I have a specimen of _Fuligo simulans_
Karsten, from Karsten himself; it is identical with my specimens of
_Fuligo ochracea_ Peck. There could be no better representation of these
specimens made at that time than the description and figure of _Fuligo
muscorum_ A. & S., in the _Conspectus_.

5. FULIGO CINEREA, Schw. Plasmodium milk-white, changing to cinereous.
Aethalium effused, variable in extent, the surface rugulose and
perforate, white, the hypothallus thin or scarcely evident. Sporangia
variously contracted and grown together, forming a dense reticulum; the
walls a thin pellucid membrane, with a thick white outer layer of
granules of lime. Capillitium a loose net-work of tubules, widely
expanded at the angles, the tubules for the most part filled, with lime,
the nodules white, numerous, very large, angular, and irregular, lobed
and branched. Spores globose or oval, minutely warted, dark violaceous,
10-15 × 10-12 mic.

Growing on old leaves, herbaceous stems, etc. I find it most abundantly
about the horse barn, upon the old straw and manure, sometimes running
out onto the green herbage. Aethalium from a few millimeters to several
centimeters in extent. Upon the testimony of Dr. Geo. A. Rex this is
both _Enteridium cinereum_ and _Lachnobolus cinereus_ of Schweinitz's
_North American Fungi_ as represented in his herbarium. It is _Physarum
ellipsosporum_ of Rostafinski. It is no doubt also _Aethaliopsis
stercoriformis_ Zopf.


IX. BADHAMIA, Berk. Sporangia large, subglobose or obovoid, sometimes
depressed, substipitate or sessile; the wall a thin membrane, with an
outer layer of minute roundish granules of lime, irregularly dehiscent.
Stipe poorly developed, sometimes a mere strip of the hypothallus, often
wanting. Capillitium of thick tubules, attached on all sides to the wall
of the sporangium, combined into a net-work of large meshes, more or
less expanded at the angles; the tubules containing minute roundish
granules of lime throughout their whole extent. Spores large,
subglobose, dark violaceous.

The peculiar character of this genus is that the granules of lime are
distributed along the whole interior of the tubules of the capillitium;
this makes the net-work rigid, and on this account a firmer support for
the wall of the sporangium.

1. BADHAMIA CAPSULIFERA, Bull. Sporangia subglobose or obovoid, sessile,
on a thin pallid or yellowish hypothallus, which sometimes sends out
narrow bands or strings of membrane of variable length, bearing
sporangia singly or in clusters. Wall of the sporangium a thin pellucid
membrane, mostly even or somewhat rugulose and iridescent, coated by a
very thin layer of white granules of lime. Capillitium of rather slender
tubules, forming an open net-work of very large meshes, only slightly
expanded at the angles; the tubules coated within by a very thin layer
of white granules of lime. Spores subglobose or obovoid, adhering
together in clusters of six to twenty or more, distinctly warted on the
outer exposed surface, dark violaceous, 10-13 mic. in diameter.

Growing on old bark, leaves, etc. Sporangia .8-1.4 mm. in diameter.
_Badhamia hyalina_ and _B. capsulifera_ of Rostafinski's monograph are
here included together; he distinguished the former by the "sporangia in
clusters always exactly globose," a distinction first made by
Chevallier; otherwise the characters are the same in both.

2. BADHAMIA UTRICULARIS, Bull. Sporangia subglobose or obovoid, sessile,
on a thin pallid or yellowish hypothallus, which often separates into
narrow strips and strings of membrane of variable length, bearing the
sporangia singly or in clusters. Wall of the sporangium a thin
violaceous membrane, rugulose and iridescent, shining with purple, blue,
and violet tints, with a thin layer of white granules of lime.
Capillitium of thick tubules, forming an open net-work of large meshes,
more or less expanded at the angles, the tubules coated within by a thin
layer of granules of lime. Spores subglobose, minutely warted, dark
violaceous, 10-13 mic. in diameter.

Growing on old wood, bark, herbaceous stems, etc. Sporangia .5-1.0 mm.
in diameter, usually growing in clusters, sometimes suspended by the
strings of membrane. Rostafinski's distinction between this and the
preceding species in regard to the spores holds good so far as my
specimens are concerned. _Badhamia magna_ Peck, I have never seen.
George Massee includes all four of these species in one composite
species, which he names _Badhamia varia_.

3. BADHAMIA PAPAVERACEA, B. & Rav. Sporangia subglobose or obovoid,
substipitate or sessile, growing close together; the wall a thin
violaceous membrane, rugulose and iridescent, with a very thin coat of
white granules of lime. Stipe very short, brown or blackish, sometimes
reduced to merely a thickened blackish base to the sporangium.
Capillitium of thick tubules, forming an open net-work of large meshes,
more or less expanded at the angles; the tubules with an inner lining of
very minute white granules of lime. Spores adhering together in clusters
of six to twenty, each spore subobovoid, the free portion more
distinctly warted, 10-12 mic. in diameter.

Growing on old wood, bark, etc. Sporangia .6-1.0 mm. in diameter.
Readily distinguished by its black base or black stipe and the elegant
clusters of its spores, which stick together most persistently.

4. BADHAMIA ORBICULATA, Rex. Sporangia much depressed, orbicular or
somewhat irregular, umbilicate often both above and below, gregarious,
sometimes growing close together and confluent, stipitate or sessile.
The wall a thin pellucid membrane, with a thin layer of minute granules
of lime, which are sometimes raised into small scales and fine ridges.
Stipe very short, black, sometimes reduced to merely a blackish base to
the sporangium. Capillitium of thick tubules, forming a scanty irregular
net-work, with wide expansions at the angles; the tubules filled with
white granules of lime. Spores subglobose, very minutely warted, dark
violaceous, 12-15 mic. in diameter.

Growing on old bark, herbaceous stems, etc. Sporangia .4-.8 mm. in
diameter, sometimes by confluence larger. This species seems near
_Badhamia verna_ Smfdt, but the latter everywhere is described as
sessile, while in the former the short black stipe is nearly always
distinguishable.

5. BADHAMIA AFFINIS, Rost. Sporangium hemispherical, or much depressed,
the base flattened or umbilicate, stipitate, erect or often cernuous;
the wall a thin pellucid membrane, coated with minute white granules of
lime, which are frequently raised into scales and ridges. Stipe short,
erect or bent at the apex, black, expanding at the base into a small
hypothallus. Capillitium of thick tubules, forming an open net-work of
large meshes, more or less expanded at the angles; the tubules filled
with white granules of lime. Spores subglobose, minutely warted, dark
violaceous, 14-18 mic. in diameter.

Growing on mosses and upon the bark of maple trunks. Sporangium .6-1.0
mm. in diameter, the stipe about the same length. Rostafinski's
description is based upon a specimen found in Chili, South America, by
Bertero; it is recorded in this country by Peck. I find it in some
seasons quite abundant. The spores are very large, in some specimens
averaging 17 mic.

6. BADHAMIA DECIPIENS, Curtis. Sporangia gregarious, sessile, globose,
oval or oblong, by confluence sometimes more elongated; the wall a
somewhat thickened and firm yellow or yellow-brown membrane, covered
with large, thick scales of lime, tawny to golden yellow or orange in
color. Capillitium of thick tubules, forming an open network, more or
less expanded at the angles; the tubules filled throughout with yellow
granules of lime. Spores globose, very minutely warted, lilac, 10-12
mic. in diameter.

Growing on old wood and bark. Sporangia .6-1.0 mm. in length by .6-.7
mm. in thickness. My specimens were determined by Dr. George A. Rex by
comparison with a specimen from Curtis in the herbarium of the
Philadelphia Academy of Sciences. This species should not be confused
with what we have described as _Physarum serpula_. _Physarum
chrysotrichum_, B. & C., is no doubt the same thing. _Badhamia nitens_
Berk., which is also golden yellow, has not yet been found in this
country; it will readily be distinguished from the present species by
its clustered spores.

7. BADHAMIA PANICEA, Fr. Sporangia sessile, subglobose or oblong, more
or less irregular, gregarious; the wall a thin, pellucid membrane,
covered with large, irregular, very thick, white scales of lime.
Capillitium of thick tubules, forming a loose net-work of rather small
meshes, with wide expansions at the angles; the tubules filled with
white granules of lime, sometimes confluent toward the base of the
sporangium. Spores subglobose, very minutely warted, dark violaceous,
11-14 mic. in diameter.

Growing on old wood, bark, leaves, etc. Sporangia .8-1.6 mm. in length,
with a thickness of .7-1.0 mm. This species appears to be rare; the only
specimens known to me in this country I have from Professor Thos. A.
Williams, of South Dakota; they are identical with European specimens
received from Lister. _Physarum paniceum_ Fries, S. M., III, p. 141; it
approaches _Physarum cinereum_ Batsch.

8. BADHAMIA LILACINA, Fr. Sporangia globose or obovoid, sessile or
rarely substipitate, closely crowded together on a thin, brownish
hypothallus; the wall a firm, hyaline membrane, with a thick, smooth,
continuous outer-layer of lime, varying in color from gray-white or drab
to lilac and flesh color. Capillitium of very thick tubules, forming a
dense net-work of small meshes; the tubules stuffed with granules of
lime, which are white or colored somewhat as those in the wall, often
confluent in the center of the sporangium. Spores globose, minutely
warted, dark violaceous, 11-14 mic. in diameter.

Growing on wood, leaves, mosses, etc. Sporangium .5-.7 mm. in diameter.
The outer crustaceous layer of lime on the wall crumbles and falls away,
as in some species of _Diderma_. The white form is _Diderma concinnum_
B. & C.; the lilac or flesh-colored form is _Physarum lilacinum_ of
Fries, S. M., p. 141. I have seen it colored only white and drab. Under
a high magnifying power the sculpturing of the spores is seen to be
peculiar.


X. SCYPHIUM, Rost. Sporangium obovoid to oblong-obovoid, stipitate or
subsessile; the wall a thickened, brownish membrane, the surface
entirely naked or only the upper portion covered with granules of lime,
breaking up irregularly about the apex. Stipe variable in length,
arising from a common hypothallus and prolonged within the sporangium as
a columella. Capillitium of thick tubules, proceeding from numerous
points of the columella and forming a dense network; the tubules filled
with lime throughout their whole extent. Spores large, subglobose, dark
reddish-brown.

This genus differs from _Badhamia_ by the columella which gives origin
to the capillitium. The sporangia in the species composing it, resemble
those of _Craterium_, and to this genus they are referred by Massee, but
the capillitium is that of _Badhamia_.

1. SCYPHIUM RUBIGINOSUM, Chev. Sporangia gregarious, obovoid, stipitate;
the wall a thickened reddish-brown membrane, the upper part covered by a
thin layer of white granules of lime, the lower basal portion naked,
strongly venulose and more persistent. Stipe long, erect, reddish-brown,
expanding at the base into a brown hypothallus, prolonged within the
sporangium to more than half its height as a columella. Capillitium of
thick tubules, forming a dense net-work of small meshes; the tubules
stuffed with white granules of lime. Spores irregularly globose,
minutely warted, dark reddish-brown, 12-15 mic. in diameter.

Growing on old wood, mosses, etc. Sporangia .6-.8 mm. in height by .5-.6
mm. in diameter, the stipe from once to twice the height of the
sporangium. This is _Physarum rubiginosum_ Chevallier, _Flor de Paris_.
It is also _Craterium obovatum_ Peck.

2. SCYPHIUM CURTISII, Berk. Sporangia oblong-obovoid, stipitate or
subsessile, usually growing in clusters; the wall a thick, firm,
reddish-brown membrane, venulose and reticulate, nearly destitute of
lime. Stipes variable, commonly very short, sometimes confluent, arising
from a brown hypothallus, prolonged within the sporangium to about half
its height. Capillitium of thick tubules, forming a dense network of
small meshes; the tubules stuffed with white granules of lime. Spores
irregularly globose, minutely warted, dark reddish-brown, 12-15 mic. in
diameter.

Growing on old wood, leaves, grass, etc. Sporangium .4-.7 mm. in height
by .3-.4 mm. in diameter, the stipe often reduced to a mere point or
cushion on the hypothallus, and varying thence to nearly the length of
the sporangium. The sporangium is narrower than in the preceding
species, and the brown wall is usually without granules of lime. It is
_Didymium curtisii_, Berk. Rostafinski and Massee both preserve it
distinct from _S. rubiginosum_. See Plate XV. Fig. 73.


EXPLANATION OF PLATE XV.

Fig. 64.--Physarum glaucum, Phillips, _a._ Sporangia × 5. _b._
Sporangium × 90. _c._ Capillitium and spores × 500.

Fig. 65.--Physarum serpula, Morgan, _a._ Plasmodiocarp × 5. _b._ Piece
of plasmodiocarp × 90. _c._ Capillitium and spores × 500.

Fig. 66.--Fuligo violacea, Pers. _a._ Aethalium natural size. _b._
Capillitium and spores × 500.

Fig 67.--Fuligo flava, Pers. _a._ Portion of an aethalium × 5. _b._
Capillitium and spores × 500.

Fig. 68.--Fuligo cinerea, Schw. _a._ Portion of aethalium × 5. _b._
Capillitium and spores × 500.

Fig. 69.--Badhamia papaveracea, B. & Rav. _a._ Sporangia × 5. _b._
Sporangium together with transverse section × 90. _c._ Capillitium and
spores × 90. _d._ Portion of capillitium with clustered spores × 500.

Fig. 70.--Badhamia affinis, Rost. _a._ Sporangia × 5. _b._ Sporangia ×
90, one with section showing capillitium. _c._ Capillitium and spores ×
500.

Fig. 71.--Badhamia decipiens, Curtis, _a._ Sporangia × 5. _b._ Sporangia
× 90. _c._ Section of sporangium showing capillitium. _d._ Capillitium
and spores × 500.

Fig. 72.--Scyphium rubiginosum, Chev. _a._ Sporangia × 90. _b._
Sporangia × 90, with section showing capillitium. _c._ Capillitium and
spores × 500.

Fig. 73.--Scyphium curtisii, Berk. Sporangia × 5.

[Illustration: The Journal of the Cin. Soc. Natural History.

  VOL. XIX.                                        PLATE XV.

MORGAN ON MYXOMYCETES.]




Transcriber's Notes


The Table of Contents and List of Illustrations was added; not part of
the original papers.

Page 4 & Vol. XV, Plate III: 'Lycogola' changed to 'Lycogala'.

Page 18: 'exigum' changed to 'exiguum'.

Page 24: 'stiptiate' changed to 'stipitate'.

Page 27: 'fasiculate' changed to 'fasciculate'.

Page 35: 'A nactium' Unknown word. Unchanged.

Vol. XVI, Plate I: 'Cookii' changed to 'Cookei'.

Page 48: 'Stermonitis scintillans' changed to 'Stemonitis scintillans'.

Page 84, 85(2): 'circumcissile' changed to 'circumscissile'.

'Network' and 'net-work' are used interchangeably throughout.

Use of accents is inconsistent, especially in illustrations.

Links to Plates XIII, XIV and XV added in html version.

Plates moved closer to referencing text.