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UNIVERSITY OF KANSAS PUBLICATIONS
MUSEUM OF NATURAL HISTORY

Volume 17, No. 11, pp. 503-515, 5 figs.
March 20, 1968



Genera of Leptodactylid Frogs in México


BY

JOHN D. LYNCH


UNIVERSITY OF KANSAS
LAWRENCE
1968




UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY

Editors: E. Raymond Hall, Chairman, Henry S. Fitch,
Frank B. Cross


Volume 17, No. 11, pp. 503-515, 5 figs.
Published March 20, 1968


UNIVERSITY OF KANSAS
Lawrence, Kansas


PRINTED BY
ROBERT R. (BOB) SANDERS, STATE PRINTER
TOPEKA, KANSAS
1968

31-9418




Genera of Leptodactylid Frogs in México

BY JOHN D. LYNCH


INTRODUCTION

According to the most recent review of the Mexican amphibian fauna
(Smith and Taylor, 1948), six genera of leptodactylid frogs occur in
México. One other genus, _Pleurodema_, occurs in Lower Central America.
Smith and Taylor recognized one species of _Engystomops_, 28 of
_Eleutherodactylus_, three of _Leptodactylus_, eight of
_Microbatrachylus_, 12 of _Syrrhophus_, and five of _Tomodactylus_.
Subsequent to the publication of their checklist of the Mexican
amphibia (1948), numerous taxonomic changes have been proposed. Many
species of _Eleutherodactylus_ have been added to the fauna, either
through the extension of their recorded ranges into México from
Guatemala or by the recognition of species unknown in 1948, whereas
some nominal species have been synonymized. _Microbatrachylus_ has been
regarded as synonymous with _Eleutherodactylus_ (Lynch, 1965); four
species of _Microbatrachylus_ currently are regarded as valid
(Duellman, 1961, Lynch, 1965). _Syrrhophus_ was revised in part by
Duellman (1958) and Firschein (1954), and a species of _Tomodactylus_
transferred to _Syrrhophus_ by Dixon (1957), who redefined
_Tomodactylus_ and added more species to the genus.

Since beginning my studies of the Mexican leptodactylids in 1962, I
have become acutely aware of difficulties involved in defining the
genera. A revision of _Eleutherodactylus_ and a review of _Syrrhophus_
are nearing completion, but prior to their publication it is desirable
to redefine the genera of the Mexican leptodactylids, and in so doing
recognize an heretofore unnamed genus. The definitions of
_Eleutherodactylus_ and _Leptodactylus_ may need to be altered in the
future, since both are widespread in South America and occur in the
West Indies. Their definitions as given here are as precise as present
knowledge permits. _Syrrhophus_ and _Tomodactylus_ are small
assemblages that occur only in southwestern United States, México, and
Guatemala.

Taylor (1952) synonymized _Engystomops_ with _Eupemphix_ which,
although related, should be regarded as generically distinct (Gallardo,
1965). Perhaps the most conservative classification is that of Myers
(1962) who, without published evidence, combined _Eleutherodactylus_,
_Syrrhophus_, and the South American _Lithodytes_ in a single genus.

The major problem for students working with the Mexican leptodactylids
has not been the separation of _Engystomops_ or _Leptodactylus_ from
other genera but the separation and definition of the eleutherodactyline
frogs currently placed in three genera, _Eleutherodactylus_,
_Syrrhophus_, and _Tomodactylus_. As will be shown in this paper, these
are more conveniently placed in four genera. Once a fourth genus is
recognized, certain phylogenetic problems disappear and a reasonable
zoogeographic interpretation is possible for Middle American
leptodactylid distribution.




ANALYSIS OF CHARACTERS


In México and northern Central America approximately 55 species of
eleutherodactyline frogs (_Eleutherodactylus_, _Syrrhophus_, and
_Tomodactylus_) are known. Four genera can be recognized on the basis
of the nature of inguinal glands, morphology of the hands and feet, and
certain osteological features.

[Illustration: FIG. 1. _Tomodactylus angustidigitorum_ (UMMZ 114305,
× 4.5) illustrating the lumbo-inguinal gland typical of members of the
genus. From a kodachrome by Wm. E. Duellman.]


Glands

Leptodactylids have a variety of glands that have been used as generic
characters. Smith and Taylor (1948) regarded the so-called inguinal
gland as a generic character in Mexican eleutherodaycty-lines. Lynch
(1965) showed that _Eleutherodactylus_ and _Microbatrachylus_ cannot
be separated by the nature of the gland or the condition of the
prevomers (dentate or not). _Syrrhophus_ and _Tomodactylus_, as defined
by Smith and Taylor (1948), are not generically distinct because of
overlap in the condition of the prevomers and in the development of the
gland. Firschein (1954) stated that _Syrrhophus_ differed from
_Tomodactylus_ by having an axillary gland, but it is now known that
one species of _Syrrhophus_ lacks the gland.

The inguinal glands of _Eleutherodactylus_ and _Syrrhophus_, if
present, are diffuse, irregular in outline, and generally not
prominent; in _Tomodactylus_ the gland is higher on the body (a
lumbo-inguinal gland), compact, oval in outline, and prominent (Fig.
1). Axillary glands occur in most _Syrrhophus_ but are not known in
_Tomodactylus_ or _Eleutherodactylus_.


Hands and feet

The tips of the digits are laterally expanded in most
_Eleutherodactylus_, _Syrrhophus_, and _Tomodactylus_. Two species
of _Eleutherodactylus_ (_augusti_ and _tarahumarensis_) and two
_Tomodactylus_ (_angustidigitorum_ and _grandis_) lack any expansion
of the digital tips. All but two of the species of eleutherodactyline
frogs (_E. augusti_ and _E. tarahumarensis_) have a transverse groove
across the tips of the digits (Fig. 2).

[Illustration: FIG. 2. Palmar views of the hands and lateral views of
the tip of the third digits of _Eleutherodactylus alfredi_ (left, KU
93994, × 5) and _Hylactophryne augusti_ (right, KU 102594, × 3).]

Supernumerary tubercles rarely are present on the feet of
_Eleutherodactylus_, but are present and numerous in every species of
_Syrrhophus_, _Tomodactylus_, and in the members of the _augusti_ group
of _Eleutherodactylus_ (Fig. 3). The tubercles are small and numerous
in _Syrrhophus_ and larger in _Tomodactylus_ and the _Eleutherodactylus
augusti_ group. Most species of _Eleutherodactylus_ have no plantar
supernumerary tubercles; a few species have such tubercles, which never
extend between the metatarsal tubercles as in _Syrrhophus_ and
_Tomodactylus_.

[Illustration: FIG. 3. Plantar views of feet of _Eleutherodactylus
alfredi_ (left, KU 93994, × 4.5), _Syrrhophus pipilans nebulosus_
(middle, KU 58900, × 7.5), and _Hylactophryne augusti_ (right, KU
102594, × 3) showing differences in size and arrangement of
supernumerary tubercles.]

Tarsal folds and tubercles are lacking in _Syrrhophus_, _Tomodactylus_,
and the _augusti_ group of _Eleutherodactylus_. Several species of
_Eleutherodactylus_ lack tarsal folds and tubercles, but in nearly
every species group, one or more species possess either an inner tarsal
fold, inner tarsal tubercle(s), or outer tarsal tubercles.

The terminal phalanges of _Syrrhophus_, _Tomodactylus_, and all
_Eleutherodactylus_ (except the frogs of the _augusti_ group) are
distinctly T-shaped. In the latter, the bones are knob-shaped distally
(Fig. 4). T-shaped terminal phalanges also are present in _Lithodytes_
and _Trachyphrynus_ but not in other leptodactylid genera. At least one
species of _Eupsophus_ (_E. quixensis_) has terminal phalanges that
resemble those of the _Eleutherodactylus augusti_ group. Several
species of _Eleutherodactylus_, _Syrrhophus_, and _Tomodactylus_ with
slender fingers have T-shaped terminal phalanges although the terminal
dilations proportionately are only scarcely wider than the finger tips
in the _Eleutherodactylus augusti_ group. The presence of a terminal
groove at the tip of the finger is an external indicator of the
T-shaped terminal phalanges.

[Illustration: FIG. 4. Terminal phalanges of four leptodactylid frogs
(all × 13.5). (a) _Eleutherodactylus mexicanus_, KU 55593; (b)
_Eupsophus roseus_, KU 84731; (c) _Eupsophus quixensis_, UIMNH 59643;
and (d) _Hylactophryne augusti_, KU 56192.]


Skull

All Mexican eleutherodactyline frogs have quadratojugal-maxillary
articulations, completely roofed skulls in adults, median contact of
the nasals, separated occipital condyles, and large prevomers. The
premaxillae of all species are visible when the skulls are viewed from
directly above. The pterygoid lacks a medioventral flange and does not
meet the palatine. In no species is the anterior arm of the squamosal
in contact with the maxillary. Of the numerous species examined (30
_Eleutherodactylus_, four _Syrrhophus_, and four _Tomodactylus_), the
species in the _Eleutherodactylus augusti_ group are unique in having a
sphenethmoid with a blunt anterior edge.


Pectoral Girdle

All species have large cartilaginous plates in the pectoral girdles;
none possesses a bony style. No divergent modifications of the clavicle
and coracoid bones are known in the family.




GENERIC ACCOUNTS


Genus ~Eleutherodactylus~ Dumeril and Bibron, 1841

     _Type-species._--_Hylodes martinicensis_ Tschudi, 1838

     _Diagnosis and definition._--Small to large frogs (12 to 110
     mm. snout-vent length) having slightly to widely expanded
     digital pads, each pad bearing a terminal transverse groove;
     lumbo-inguinal, inguinal, and axillary glands absent, or if
     present, diffuse, irregular in outline, not compact; plantar
     supernumerary tubercles absent, or if present, six or fewer,
     restricted to distal area of plantar surface, and not
     extending between metatarsal tubercles; tarsus bearing inner
     or outer tubercles or folds or not; toes free to one-half
     webbed; terminal phalanges T-shaped; sternum cartilaginous,
     lacking bony style; sphenethmoid not truncate anteriorly;
     nasals in contact medially; maxillary and quadratojugal in
     contact; anterior arm of squamosal not in contact with
     maxillary; dermal cranial elements not involved in
     integumentary-cranial co-ossification; prevomers large,
     dentigerous processes present or not, dentate or not;
     maxillary and premaxillary bones dentate; occipital condyles
     separated; development direct.

     _Composition._--About 420 names have been applied to frogs
     of this genus; many of these names are synonyms, and many
     other species remain undescribed and unnamed. Perhaps the
     genus contains 350 species. Thirty-one species occur in
     México and northern Central America.

     _Distribution._--From Tamaulipas and Sinaloa, México,
     exclusive of the Mexican Plateau, to at least Peru and
     southernmost Brazil and throughout the West Indies.
     Introduced into Florida.

     _Etymology._--Greek (_eleuthero_ + _dactylus_) meaning
     free-toed.


Genus ~Engystomops~ Jiménez de la Espada, 1872

     _Type species._--_Engystomops petersi_ Jiménez de la Espada,
     1872

     _Diagnosis and definition._--Small frogs (20 to 40 mm.
     snout-vent length) having undilated digital tips lacking
     transverse grooves; lumbo-inguinal or inguinal glands
     absent; plantar supernumerary tubercles present, extending
     between metatarsal tubercles; tarsus bearing spinelike
     tubercle on inner edge; toes free; terminal phalanges
     pointed; sternum bearing bony style; spenethmoid not
     truncate anteriorly; nasals in contact medially; maxillary
     and quadratojugal in articular contact; anterior arm of
     squamosal not in contact with maxillary; dermal cranial
     elements not involved in integumentary-cranial
     co-ossification; prevomers moderate in size, lacking teeth;
     maxillary and premaxillary bones edentate; occipital
     condyles separated; tadpole free living.

     _Composition._--Four nominal species (_E. petersi_, _E.
     pustulatus_, _E. pustulosus_ and _E. schereri_).

     _Distribution._--Central Veracruz and eastern Oaxaca,
     México, to Trinidad, Bolivia, and Peru, east of the Andes.

     _Etymology._--Greek (_engys_ + _stoma_) meaning narrow-mouthed.


Genus ~Hylactophryne~ new genus

     _Type-species._--_Hylodes augusti_ Dugés, 1879

     _Diagnosis and definition._--Medium to large frogs (37 to 94
     mm. snout-vent length) having undilated digital tips lacking
     terminal grooves; lumbo-inguinal or inguinal glands absent;
     plantar supernumerary tubercles present, prominent,
     extending to but not between metatarsal tubercles; tarsus
     lacking tubercles or folds; toes free of webbing; terminal
     phalanges knob-shaped, lacking elongate lateral expansions;
     sternum cartilaginous, lacking bony style; sphenethmoid
     truncate anteriorly; nasals in contact medially; maxillary
     and quadratojugal in articular contact; anterior arm of
     squamosal not in contact with maxillary; dermal cranial
     elements not involved in integumentary-cranial
     co-ossification; prevomers large, bearing dentigerous
     processes; maxillary and premaxillary bones dentate;
     occipital condyles separated; development direct.

     _Composition._--Two species, _H. augusti_ and _H.
     tarahumarensis_, the former composed of four subspecies
     (Zweifel, 1956).

     _Distribution._--From Arizona, New Mexico, and Texas to
     Guerrero and Puebla, México, and a relict population on
     Cerro Quingola (just west of the Isthmus of Tehuantepec,
     México).

     _Etymology._--Greek (_hylactor_ + _phryne_) meaning barking
     toad; in reference to the voice and common name.


Genus ~Leptodactylus~ Fitzinger, 1826

     _Type-species._--_Leptodactylus typhonia_ Fitzinger, 1826

     _Diagnosis and definition._--Small to large frogs (30 to
     about 200 m., snout-vent length) having undilated to
     slightly expanded digital tips bearing pads, no transverse
     groove at tips of digits; lumbo-inguinal, axillary, and/or
     ventral glands present or not, low, diffuse; plantar
     supernumerary tubercles generally absent, if present not
     extending between metatarsal tubercles; tarsus bearing
     tarsal folds or not; toes free of webbing, extensive lateral
     fringes present in some species; terminal phalanges pointed,
     not T-shaped; sternum bearing bony style; sphenethmoid not
     truncate anteriorly; nasals in contact medially; maxillary
     and quadratojugal in articular contact; anterior arm of
     squamosal not in contact with maxillary; dermal cranial
     elements not involved in integumentary-cranial
     co-ossification; prevomers large, bearing dentigerous
     processes; maxillary and premaxillary bones dentate;
     occipital condyles separated; tadpole free living.

     _Composition._--Sixty species according to Smith and Taylor
     (1948); 54 according to Gorham (1963); Argentinian authors
     have described several more in recent years.

     _Distribution._--Southern Sonora, México, and southern Texas
     throughout the Central and South American lowlands to
     Argentina. Also known from Hispaniola and Puerto Rico in the
     Greater Antilles and a few islands in the Lesser Antilles.

     _Entymology._--Greek (_leptos_ + _dactylus_) meaning slender
     toes.


Genus ~Syrrhophus~ Cope, 1878

     _Type-species._--_Syrrhophus marnockii_ Cope, 1878

     _Diagnosis and definition._--Small to medium sized frogs (18
     to 40 mm. snout-vent) having slight to prominent digital
     expansions with transverse groove at tip of each digit;
     lumbo-inguinal and inguinal gland flattened, irregular in
     outline, not compact and oval; axillary glands present or
     not; plantar supernumerary tubercles numerous, more than
     eight, usually extending between metatarsal tubercles;
     tarsus lacking tubercles or folds; toes free or basally
     webbed; terminal phalanges T-shaped; sternum cartilaginous,
     lacking bony style; sphenethmoid not truncate anteriorly;
     nasals in contact medially; maxillary and quadratojugal in
     articular contact; anterior arm of squamosal not in contact
     with maxillary; dermal cranial elements not involved in
     integumentary-cranial co-ossification; prevomers large,
     usually lacking dentigerous processes and teeth; maxillary
     and premaxillary bones dentate; occipital condyles
     separated; development direct.

     _Composition._--Thirteen species; the species described as,
     or later referred to, _Syrrhophus_ from Lower Central
     America and South America are _Eleutherodactylus_ or
     _Eupsophus_.

     _Distribution._--Low to moderate elevations from Sinaloa,
     México, to Guatemala on the Pacific versant; from the
     Edwards and Stockton plateaus of Texas to British Honduras
     on the Caribbean versant.

     _Etymology._--Greek, emendation of _syrrhaptos_, meaning
     sewn together in reference to the united outer metatarsals.


Genus ~Tomodactylus~ Günther, 1900

     _Type-species._--_Tomodactylus amulae_ Günther, 1900.

     _Diagnosis and definition._--Small frogs (20 to 35 mm.
     snout-vent length) having digital expansions or not, with
     transverse groove across tip of each digit; lumbo-inguinal
     gland prominently elevated, compact, oval, often patterned;
     axillary glands absent; plantar supernumerary tubercles
     numerous, more than eight, usually extending between
     metatarsal tubercles; tarsus lacking tubercles or folds; toes
     free; terminal phalanges T-shaped; sternum cartilaginous,
     lacking bony style; sphenethmoid not truncate anteriorly;
     nasals in contact medially; maxillary and quadratojugal in
     articular contact; anterior arm of squamosal not in contact
     with maxillary; dermal cranial elements not involved in
     integumentary-cranial co-ossification; prevomers large,
     usually bearing dentigerous processes; maxillary and
     premaxillary bones dentate; occipital condyles separated;
     development direct.

     _Composition._--Ten species.

     _Distribution._--The southern edge of the Mexican Plateau
     from Sinaloa to Veracruuz and onto the Oaxaca highlands and
     Sierra Madre del Sur.

     _Etymology._--Greek (_tomis_ + _dactylus_) meaning knife
     toe; in reference to either the sharp subarticular tubercles
     or the unwebbed toes.




DISCUSSION


The preceding definitions only slightly alter the present generic
limits of Mexican leptodactylids. Two species, previously regarded as
_Eleutherodactylus_, are transferred to the new genus _Hylactophryne_.
The arrangement of the species of _Syrrhophus_ and _Tomodactylus_
remains the same as concluded by Dixon (1957), Duellman (1958), and
Firschein (1954) in their reviews of the genera.

Lumbo-inguinal glands are most prominent in the genera _Pleurodema_ and
_Tomodactylus_. Various nondescript glands are present in many genera,
but none is so well developed as those of _Pleurodema_ and
_Tomodactylus_.

At least nine leptodactylid genera are either known or thought to be
terrestrial breeders lacking a free-living tadpole stage
(_Eleutherodactylus_, _Euparkerella_, _Hylactophryne_, _Niceforonia_,
_Noblella_, _Sminthillus_, _Syrrhophus_, _Tomodactylus_ and
_Trachyphrynus_). _Niceforonia_ and _Trachyphrynus_, and probably
_Hylactophryne_, are not closely related to the other genera. Direct
development probably is an adaptation to adverse environmental
conditions since many of the species occur in semi-arid or cold (Andean
páramos) areas. _Eleutherodactylus_ is generally thought to be the
stock from which _Euparkerella_, _Noblella_, and _Sminthillus_ evolved
(Griffiths, 1959) and from which _Syrrhophus_ and _Tomodactylus_ are
derived (Firschein, 1954).

The present distribution of _Hylactophryne_ (isolated on the Mexican
Plateau) and its digital form (like that of Papuan and many primitive
South American leptodactylids) suggest that the genus was isolated in
México throughout the Tertiary, whereas the other Central American
genera are either post-Pliocene derivatives of _Eleutherodactylus_ or
invaders of Central America from South America since the mid-Pliocene
land bridge was formed (Lloyd, 1963).

Piatt (1934) presented arguments against assigning _Eleutherodactylus
latrans_ to the genus _Lithodytes_ and concluded that it was a "true"
_Eleutherodactylus_. Contrary to his arguments, _latrans_ (= _augusti_
of Zweifel) and _E. tarahumarensis_ Taylor differ from all other
_Eleutherodactylus_ (and _Syrrhophus_ and _Tomodactylus_) in the nature
of the tips of the digits (external and skeletal). The digits of
_Hylactophryne_ are like those of _Eupsophus_. My study of nearly all
genera of leptodactylids indicates that Noble (1925) was correct in
suggesting that _Borborocoetes_ (= _Eupsophus_) is a close relative of
_Eleutherodactylus latrans_, although Noble's arguments were based in
part upon false evidence concerning the breeding habits of _E.
latrans_, then thought to have a free-living tadpole.

Kellogg (1932) and Piatt (1934) argued that the terminal phalanges of
_E. latrans_ were typically eleutherodactyline. The variation of this
character in _Eupsophus_ (see Fig. 4) ranges from knobbed to bifurcate
or Y-shaped (T-shaped in _Eleutherodactylus_, _Syrrhophus_ and
_Tomodactylus_) and encompasses the nature of the character represented
in _Hylactophryne_. _Eupsophus_ differs from _Hylactophryne_ in
possessing a frontoparietal fontanelle, in generally having a
maxillary-quadratojugal gap, and in having a free swimming tadpole
stage.

[Illustration: FIG. 5. Outline drawings of _Leptodactylus melanonotus_
(left, KU 65704, × 2) and _Eleutherodactylus alfredi_ (right, KU 93994,
× 2).]




KEY TO MEXICAN LEPTODACTYLID GENERA


1. Small (20-40 mm.), pustular, toadlike frogs;
   maxillary and premaxillary bones not bearing teeth    _Engystomops_

   Large (20-110 mm.), smooth skinned and non-toadlike
   frogs; maxillary and premaxillary bones bearing teeth            2

2. No conspicuous waist (Fig. 5); sternum bearing
   bony style,                                         _Leptodactylus_

   Constrictions at waist (Fig. 5); sternum
   cartilaginous, no bony style                                     3

3. Few (less than six), if any, supernumerary
   tubercles on plantar surface                    _Eleutherodactylus_

   Many (more than 8) supernumerary tubercles on
   plantar surfaces                                                 4

4. Terminal, transverse groove across tip of
   digits, especially outer two fingers, digits
   expanded or not; small frogs (18 to 40 mm.)                      5

   Tips of digits lacking transverse groove;
   digits unexpanded; medium-sized to large frogs
   (37 to 94 mm.)                                      _Hylactophryne_

5. Lumbo-inguinal gland compact, oval                   _Tomodactylus_

   Lumbo-inguinal or inguinal gland absent or
   diffuse and irregular in outline                       _Syrrhophus_




LITERATURE CITED


DIXON, J. R.

     1957. Geographic variation and distribution of the genus
           _Tomodactylus_ in Mexico. Texas Jour. Sci., 9:379-409,
           December.

DUELLMAN, W. E.

     1958. A review of the frogs of the genus Syrrhophus in
           western Mexico. Occas. Papers Mus. Zool. Univ.
           Michigan, 594:1-15, June 6.

     1961. The amphibians and reptiles of Michoacan, Mexico. Univ.
           Kansas Publ. Mus. Nat. Hist., 15:1-148, December 20.

FIRSCHEIN, I. L.

     1954. Definition of some little understood members of the
           leptodactylid genus _Syrrhophus_, with a description
           of a new species. Copeia, 1:48-58, February 19.

GALLARDO, J. M.

     1965. A proposito de los Leptodactylidae (Amphibia Anura).
           Papeis Avulsos, 17:77-87, January 30.

GORHAM, S. W.

     1963. The comparative number of species of amphibians in
           Canada and other countries. III. Summary of species
           of anurans. Canadian Field-Nat., 77:13-48, March.

GRIFFITHS, I.

     1959. The phylogeny of Sminthillus limbatus and the status of
           the Brachycephalidae (Amphibia Salientia). Proc. Zool.
           Soc. London, 132:457-87, May.

KELLOGG, R.

     1932. Mexican tailless amphibians in the United States
           National Museum. Bull. U. S. Natl. Mus., 160:224 pp.,
           March 31.

LLOYD, J. J.

     1963. Tectonic history of the south Central-American orogen,
           _in_ Childs and Beebe eds., Backbone of the Americas.
           Amer. Assoc. Petroleum Geol., pp. 88-100.

LYNCH, J. D.

     1965. A review of the eleutherodactylid frog genus
           _Microbatrachylus_ (Leptodactylidae). Nat. Hist. Misc.,
           182:1-12, December 15.

MYERS, G. S.

     1962. The American leptodactylid frog genus _Eleutherodactylus_,
           _Hylodes_ (= _Elosia_), and _Caudiverbera_
           (= _Calytocephalus_). Copeia, 1:195-202, April 11.

NOBLE, G. K.

     1925. An outline of the relation of the ontogeny to
           phylogeny within the Amphibia. I. Amer. Mus. Nov.,
           165:1-17, April 16.

PIATT, J.

     1934. The systematic status of Eleutherodactylus latrans
           (Cope). Amer. Midl. Nat., 15:89-91, February 15.

SMITH, H. M. and TAYLOR, E. H.

     1948. An annotated checklist and key to the Amphibia of
           Mexico. Bull. U. S. Natl. Mus., 194:1-118. June 7.

TAYLOR, E. H.

     1952. A review of the frogs and toads of Costa Rica. Univ.
           Kansas Sci. Bull., 35:577-942, July 1.

ZWEIFEL, R. G.

     1956. A survey of the frogs of the _augusti_ group, genus
           _Eleutherodactylus_. Amer. Mus. Novitates, 1813:1-35,
           December 23.


_Transmitted July 11, 1967._


31-9418




       *       *       *       *       *

Transcriber's Notes


Bold text is shown within ~tildes~.

Italicized text is shown within _underscores_.

Illustrations have been moved to avoid breaking up paragraphs of text.

Page 507: Changed know to known (are not know in Tomodactylus).

Page 507: Added closing parenthesis in Fig. 2 caption after × 3.

Page 509: Changed compeltely to completely (compeltely roofed skulls).

Page 512: Veracruuz may be a typo for Veracruz (Sinaloa to Veracruuz).

Page 514: Changed two occurrences of Hylatophryne to Hylactophryne.