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 UNIVERSITY OF KANSAS
 MUSEUM OF NATURAL HISTORY

 Vol. 20, No. 1, pp. 1-45, 22 figs.

 February 20, 1970

 A Taxonomic Revision
 of the Leptodactylid Frog Genus
 Syrrhophus Cope

 BY

 JOHN D. LYNCH

 UNIVERSITY OF KANSAS
 LAWRENCE
 1970




 UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY

 Editors of this number:
 Frank B. Cross, Philip S. Humphrey, William E. Duellman

 Volume 20, No. 1, pp. 1-45, 22 figs.
 Published February 20, 1970

 UNIVERSITY OF KANSAS
 Lawrence, Kansas

 PRINTED BY
 THE UNIVERSITY OF KANSAS PRINTING SERVICE
 LAWRENCE, KANSAS
 1970




A Taxonomic Revision of the Leptodactylid Frog Genus Syrrhophus Cope

BY

JOHN D. LYNCH




INTRODUCTION


Cope (1878) proposed the genus _Syrrhophus_ for a medium-sized
leptodactylid frog from central Texas; in the ensuing 75 years the genus
was expanded to include a heterogeneous group of frogs ranging from
Texas to Peru. Taylor (1952) and Firschein (1954) limited the genus to
several species of frogs occurring in Guatemala, México, and Texas.
Lynch (1968) provided a definition of the previously loosely-defined
genus.

With the exception of Taylor (1952), who treated the Costa Rican
species, none of these authors dealt with the present status of the
nineteen species erroneously assigned to _Syrrhophus_. These species are
listed in Tables 1 and 2 with the name currently applied. Some of them
are new combinations and their justifications will be published
elsewhere. Gorham (1966) is the most recent author to include South
American species in the genus _Syrrhophus_.

Smith and Taylor (1948) recognized two species groups of the genus in
México, an eastern and a western group (here termed complexes for
purposes of discussion), separated on the basis of the number of palmar
(metacarpal) tubercles (three palmar tubercles in the members of the
eastern complex and two in those of the western complex). Duellman
(1958) reviewed the species of the genus occurring in western México and
concluded that there were five species (two polytypic). Dixon and Webb
(1966) described an additional species from Jalisco, México. The
distributions of some species have been extended, but otherwise the
western complex of species remains unchanged since Duellman's review.

Smith and Taylor (1948) recognized seven species of the genus in eastern
México. Firschein revised the eastern complex (as then understood), and
in so doing added one new species and treated _Syrrhophus verruculatus_
as a _nomen dubium_. Dixon (1957) redefined the related genus
_Tomodactylus_ and transferred _T. macrotympanum_ Taylor to the genus
_Syrrhophus_. Neill (1965) described a new subspecies of _S. leprus_
from British Honduras. Two species (_S. gaigeae_ and _S. marnockii_)
were recognized in Texas until Milstead, Mecham, and McClintock (1950)
synonymized _S. gaigeae_ with _S. marnockii_. Thus, at present, nine
species (one polytypic) are recognized on the eastern slopes and
lowlands from central Texas to British Honduras. These are currently
placed on one species group equivalent to the western complex reviewed
by Duellman (1958).


 TABLE 1--Species Described as Members of the Genus _Syrrhophus_ but
   Now Placed in Other Genera.

 =======================================================================
 Trivial name and author           Current combination
 -----------------------------------------------------------------------
 _areolatus_ Boulenger, 1898       _Eleutherodactylus areolatus_
 _calcaratus_ Andersson, 1945      _Eleutherodactylus anderssoni_
 _caryophyllaceus_ Barbour, 1928   _Eleutherodactylus caryophyllaceus_
 _coeruleus_ Andersson, 1945       _Eleutherodactylus coeruleus_
 _ineptus_ Barbour, 1928           _Eleutherodactylus diastema_
 _juninensis_ Shreve, 1938         _Eupsophus juninensis_
 _lutosus_ Barbour and Dunn, 1921  _Eleutherodactylus lutosus_
 _molinoi_ Barbour, 1928           _Eleutherodactylus molinoi_
 _montium_ Shreve, 1938            _Niceforonia montia_
 _mystaceus_ Barbour, 1922         _Eleutherodactylus rhodopis_
 _obesus_ Barbour, 1928            _Eleutherodactylus punctariolus_
 _omiltemanus_ Gunther, 1900       _Eleutherodactylus omiltemanus_[1]
 _pardalis_ Barbour, 1928          _Eleutherodactylus pardalis_
 =======================================================================

 [1] New combination.


 TABLE 2--Species Incorrectly Regarded as Members of the Genus _Syrrhophus_
   but Described as Members of Other Genera.

 ==========================================================================
 Trivial name, original generic
 assignment, and author                     Current combination
 --------------------------------------------------------------------------
 _chalceus_ (_Phyllobates_) Peters, 1873    _Eleutherodactylus chalceus_
 _festae_ (_Paludicola_) Peracca, 1904      _Niceforonia festae_
 _hylaeformis_ (_Phyllobates_) Cope, 1875   _Eleutherodactylus hylaeformis_
 _palmatus_ (_Phyllobates_) Werner, 1899    _Colostethus palmatus_
 _ridens_ (_Phyllobates_) Cope, 1866        _Eleutherodactylus ridens_
 _simonsii_ (_Paludicola_) Boulenger, 1900  _Niceforonia simonsii_
 ==========================================================================


 TABLE 3--Nominal Species of _Syrrhophus_ (_sensu strictu_) and the Name
   Used Herein.

 =======================================================================
 Original combination                  Current combination
 -----------------------------------------------------------------------
 _campi_, _Syrrhophus_                 _cystignathoides campi_
 _cholorum_, _Syrrhophus leprus_       _leprus_
 _cystigathoides_, _Phyllobates_       _cystignathoides cystignathoides_
 _dennisi_, _Syrrhophus_               _dennisi_ new species
 _gaigeae_, _Syrrhophus_               _guttilatus_
 _guttilatus_, _Malachylodes_          _guttilatus_
 _interorbitalis_, _Syrrhophus_        _interorbitalis_
 _latodactylus_, _Syrrhophus_          _longipes_
 _leprus_, _Syrrhophus_                _leprus_
 _longipes_, _Batrachyla_              _longipes_
 _macrotympanum_, _Tomodactylus_       _verrucipes_
 _marnockii_, _Syrrhophus_             _marnockii_
 _modestus_, _Syrrhophus_              _modestus_
 _nebulosus_, _Syrrhophus_             _pipilans nebulosus_
 _nivocolimae_, _Syrrhophus_           _nivocolimae_
 _pallidus_, _Syrrhophus modestus_     _pallidus_
 _petrophilus_, _Syrrhophus_           _guttilatus_
 _pipilans_, _Syrrhophus_              _pipilans pipilans_
 _rubrimaculatus_, _Syrrhophus_        _rubrimaculatus_
 _smithi_, _Syrrhophus_                _guttilatus_
 _teretistes_, _Syrrhophus_            _teretistes_
 _verrucipes_, _Syrrhophus_            _verrucipes_
 _verruculatus_, _Phyllobates_         _Nomen dubium_
 =======================================================================


In the course of preparing an account of the species of
_Eleutherodactylus_ occurring in México and northern Central America, it
became necessary to reëxamine the status of the genus _Syrrhophus_ and
its nominal species. It soon became evident that there were more names
than species, that some previously regarded species were geographic
variants, and that the eastern and western groups (complexes here) were
artificial divisions of the genus. I conclude that there are seven
species (one polytypic) of _Syrrhophus_ in eastern México, Texas, and El
Petén of Guatemala, and seven species (one polytypic) in western México.
The current status of each of the 23 names correctly assigned to the
genus is presented in Table 3.

The fourteen species recognized by me are placed in five species groups.
Two of these groups are presently placed in the western complex
(_modestus_ and _pipilans_ groups) and three in the eastern complex
(_leprus_, _longipes_ and _marnockii_ groups). The two complexes do
not correspond exactly with the eastern and western groups of Smith
and Taylor (1948), Firschein (1954), and Duellman (1958) since
_S. rubrimaculatus_ is now associated with the eastern _leprus_ group.

The definitions and contents of the five species groups are as follows:

  _leprus_ group: digital pads not or only slightly expanded, rounded
     in outline; first finger longer or shorter than second; snout
     acuminate or subacuminate, not rounded; outer metatarsal tubercle
     conical; digits lacking distinct lateral fringes.

     content: _cystignathoides_, _leprus_ and _rubrimaculatus_.

  _longipes_ group: digital pads widely expanded, triangular in outline;
     first finger shorter than second; snout acuminate; outer metatarsal
     tubercle not conical; digits bearing lateral fringes.

     content: _dennisi_ and _longipes_.

  _marnockii_ group: digital pads expanded, rounded to truncate in
     outline; first finger equal in length to second or slightly shorter;
     snout rounded; outer metatarsal tubercle not conical; digits lacking
     lateral fringes; generally stout-bodied frogs.

     content: _guttilatus_, _marnockii_, and _verrucipes_.

  _modestus_ group: digital pads expanded, truncate in outline; first and
     second fingers subequal in length, first usually slightly shorter
     than second; snout subacuminate; inner metatarsal tubercle twice as
     large (or larger) as outer metatarsal tubercle; digits bearing
     poorly-defined lateral fringes.

     content: _interorbitalis_, _modestus_, _nivocolimae_, _pallidus_,
     and _teretistes_.

  _pipilans_ group: digital pads not or only slightly expanded,
     truncate in outline; first finger equal in length to second; snout
     subacuminate; metatarsal tubercles subequal in size; digits lacking
     lateral fringes.

     content: _pipilans_.


_Acknowledgments._--For loan of specimens, I am indebted to Richard J.
Baldauf, Texas A & M University (TCWC); W. Frank Blair, University of
Texas (TNHC); Charles M. Bogert and Richard G. Zweifel, American Museum
of Natural History (AMNH); James E. Böhlke and Edmond V. Malnate,
Academy of Natural Sciences of Philadelphia (ANSP); Robert F. Inger and
Hymen Marx, Field Museum of Natural History (FMNH); Ernest A. Liner
(EAL); Michael Ovchynnyk, Michigan State University collection (MSU);
James A. Peters, United States National Museum (USNM); Douglas A.
Rossman, Louisiana State University Museum of Zoology (LSUMZ); Hobart M.
Smith, University of Illinois Museum of Natural History (UIMNH); Charles
F. Walker, University of Michigan Museum of Zoology (UMMZ); and John W.
Wright, Los Angeles County Museum (LACM). Specimens in the collection at
the University of Kansas Museum of Natural History are identified as KU.
The abbreviations EHT-HMS refer to the Edward H. Taylor-Hobart M. Smith
collection and FAS to the Frederick A. Shannon collection. The
type-specimens from these collections are now in the Field Museum of
Natural History and the University of Illinois Museum of Natural
History.

I have profited from discussions concerning this problem with several
persons, most notably William E. Duellman, Hobart M. Smith, Edward H.
Taylor and Charles F. Walker. Nevertheless, the ideas and conclusions
presented here should not be construed as necessarily reflecting their
opinions.

David M. Dennis executed all of the figures, and my wife, Marsha, typed
the manuscript.


_Materials and Methods._--In the course of this study, 1003 specimens
of the genus were examined. The holotypes of 21 of the 23
nominal species are extant; I have examined 19 of these. Nine
measurements were taken, and five ratios computed for each of 338
specimens. Females are available for all species but one; thus,
measurements were taken on individuals of both sexes.




ANALYSIS OF CHARACTERS


_Size and proportions._--Frogs of this genus range in size from 16
to 40 mm. in snout-vent length. Five species are relatively small:
_S. cystignathoides_, _modestus_, _nivocolimae_, _pallidus_ and
_rubrimaculatus_; one, _S. longipes_, is relatively large, and the
remaining eight species are intermediate in size (22-30 mm.).

Males are generally smaller than females and have proportionately longer
heads and usually larger tympani. No significant differences were found
among proportions, except that _S. longipes_ has a larger tympanum/eye
ratio than any other species. Frogs in the _Syrrhophus marnockii_ group
tend to have shorter shanks and feet, thereby giving those species a
more stocky appearance. However, the differences are not significant.

A summary of the data on size and proportions for the frogs of the genus
_Syrrhophus_ is given in Tables 4, 5, and 6.


_Hands and Feet._--Taylor and Smith (1945), Smith and Taylor (1948),
Firschein (1954) and Duellman (1958) discussed the value of the palmar
tubercles in identifying frogs of this genus. The eastern complex in
general has a well-developed outer palmar tubercle (Fig. 1) in
distinction to the western complex in which the outer palmar tubercle is
reduced or absent (Fig. 2). Dixon and Webb (1966) imply that the outer
palmar tubercle is rarely absent but is usually smaller than the first
supernumerary tubercle of the fourth finger. My study of the western
species demonstrates that the outer palmar tubercle is indeed usually
present and smaller than the first supernumerary tubercle.

Differences in interpretation of the terms "unexpanded" and "narrow," as
well as differences in techniques of preservation, have led to confusion
of the reported digital shapes in various species. Constant specific
differences are evident in the hands (Fig. 1). Except in the cases of
excessive uptake of fluids, all species have a terminal transverse
groove at the tip of each digit. Taylor (1940b) stated that _S. smithi_
lacked grooves, but examination of the holotype reveals faint grooves at
the tops of the digits. _Syrrhophus guttilatus_, _leprus_, _pipilans_,
and _verrucipes_ lack lateral fringes on the fingers. Lateral fringes
are well developed in the _longipes_ and _modestus_ groups but poorly
defined or absent in the other members of the genus. The digital pads of
the frogs of the _longipes_ group are much broader than those of the
other species and are narrowest in the frogs of the _leprus_ group.
Supernumerary tubercles are present on the palmar surfaces of all
species of the genus.


 TABLE 4--Size and Proportions in the Frogs of the _Syrrhophus leprus_
   Group.

   A: _cystignathoides campi_
   B: _c. cystignathoides_
   C: _leprus_
   D: _rubrimaculatus_

 ==========================================================================
                  Snout-vent   Tibia      Head     Tympanum/    Eyelid/
                    length    length/    width/      Eye     Interorbital
 Species  Sex  N    (SVL)       SVL       SVL
 --------------------------------------------------------------------------
    A     [M]  33  16.3-23.5  41.3-49.6  34.0-40.1  43.7-66.5   43.2-89.6
                                 (45.8)     (37.0)    (56.2)      (61.5)
          [F]  12  16.0-25.8  41.5-51.0  33.0-38.0  42.8-60.0   48.2-69.2
                                 (45.8)     (35.0)    (51.2)      (60.1)
    B     [M]  15  16.8-22.1  45.1-50.4  33.2-40.7  44.3-68.7   44.6-65.4
                                 (47.3)     (37.8)    (54.8)      (60.0)
          [F]   6  19.6-24.2  46.4-50.0  34.1-38.1  43.3-56.5   53.2-65.4
                                 (47.6)     (36.2)    (46.9)      (59.2)
    C     [M]  14  20.6-26.4  42.3-52.3  35.0-40.3  47.5-62.5   58.2-72.5
                                 (46.8)     (37.4)    (56.5)      (67.3)
          [F]  15  22.1-29.2  43.4-53.3  32.6-38.9  38.6-57.9   50.2-86.9
                                 (47.1)     (35.8)    (47.1)      (68.1)
    D     [M]  12  18.2-23.5  40.4-46.2  31.8-35.5  35.5-46.5   65.1-78.5
                                 (43.4)     (33.8)    (41.7)      (71.7)
 ==========================================================================


 TABLE 5--Size and Proportions in the Frogs of the _Syrrhophus longipes_
   and _S. marnockii_ Groups.

   A: _dennisi_
   B: _longipes_
   C: _guttilatus_
   D: _marnockii_
   E: _verrucipes_

 ==========================================================================
                  Snout-vent   Tibia      Head     Tympanum/    Eyelid/
                    length    length/    width/      Eye     Interorbital
 Species  Sex  N    (SVL)       SVL       SVL
 --------------------------------------------------------------------------
    A     [M]   16  22.8-28.4  43.9-49.7  35.3-41.2  53.9-64.2   55.3-74.0
                                 (47.4)     (38.8)     (58.9)      (65.1)
          [F]   10  25.9-32.0  46.3-50.8  35.6-40.3  50.6-58.7   58.1-70.9
                                 (48.2)     (37.7)     (54.9)      (63.6)
    B     [M]   22  22.1-33.2  45.8-51.7  38.7-44.4  61.1-87.2   61.5-83.0
                                 (48.4)     (41.8)     (72.0)      (72.0)
          [F]   19  26.8-39.6  44.3-51.0  36.3-40.8  49.5-72.1   55.3-85.9
                                 (47.2)     (39.1)     (59.5)      (67.9)
    C     [M]   19  20.6-29.0  41.2-48.1  36.9-44.9  55.1-75.7   53.3-79.5
                                 (44.5)     (40.6)     (64.1)      (66.0)
          [F]    5  25.7-31.0  41.4-46.8  35.9-42.3  47.6-61.7   62.3-79.8
                                 (43.6)     (38.5)     (54.0)      (72.9)
    D     [M]   14  18.4-28.9  42.3-47.2  36.1-43.0  47.2-68.3   51.6-74.4
                                 (44.1)     (39.6)     (61.2)      (66.3)
          [F]   29  20.4-35.4  38.7-46.4  35.9-41.3  45.8-73.3   52.1-70.5
                                 (42.7)     (38.2)     (60.3)      (60.7)
    E     [M]   29  17.5-29.2  42.7-49.5  36.2-42.4  56.1-82.2   56.8-82.8
                                 (46.3)     (39.1)     (67.8)      (70.4)
          [F]    6  26.5-31.7  42.4-47.7  36.0-38.1  45.8-57.8   61.0-77.9
                                 (44.6)     (37.0)     (53.9)      (69.0)
 ==========================================================================


 TABLE 6--Size and Proportions in the Frogs of the _Syrrhophus pipilans_
   and _S. modestus_ Groups.

   A: _pipilans nebulosus_
   B: _pipilans pipilans_
   C: _modestus_
   D: _pallidus_
   E: _teretistes_
   F: _nivocolimae_
   G: _interorbitalis_

 ==========================================================================
                  Snout-vent   Tibia      Head     Tympanum/    Eyelid/
                    length    length/    width/      Eye     Interorbital
 Species  Sex  N    (SVL)       SVL       SVL
 --------------------------------------------------------------------------
    A     [M]   17  22.9-28.5  38.1-42.0  34.4-37.2  36.6-47.8   56.1-82.4
                                 (40.0)     (35.4)     (43.6)      (68.2)
          [F]    3  21.1-22.7  42.1-44.5  33.2-35.8  36.6-47.6   64.3-65.4

    B     [M]   18  22.6-27.8  37.9-44.0  32.2-36.5  38.0-54.0   56.1-79.5
                                 (41.4)     (33.0)     (46.2)      (67.3)
          [F]    1     29.4       38.4       32.5       44.6        55.0

    C     [M]    8  15.8-20.1  38.5-42.6  32.1-38.1  26.8-39.3   57.0-86.9
                                 (40.6)     (34.2)     (31.5)      (69.1)
          [F]    1     18.5       44.2       36.0       24.0        52.1

    D     [M]    6  17.9-19.3  41.0-44.9  32.6-36.2  27.0-35.6   59.4-67.7
                                 (43.4)     (35.2)     (30.9)      (65.2)

    E     [M]   18  19.2-23.2  41.5-45.3  32.5-36.4  28.6-43.8   51.2-75.0
                                 (43.7)     (34.0)     (33.7)      (62.2)
          [F]    1     24.8       41.8       30.8       37.9        60.5

    F     [M]   15  18.9-21.1  42.2-48.6  30.9-37.1  30.0-39.3   42.6-69.1
                                 (45.0)     (33.7)     (34.7)      (55.0)
          [F]    1     24.1       40.9       33.5       27.6        56.5

    G     [M]    1     25.6       43.0       ----       39.4        57.6
          [F]    9  20.2-26.7  39.9-47.1  32.6-39.3  29.1-41.2   58.2-76.9
                                 (43.2)     (35.8)     (36.4)      (69.2)
 ==========================================================================


    [Illustration: FIG. 1: Palmar views of hands of six species of the
       eastern complex of _Syrrhophus_. (A) _verrucipes_ (UIMNH 15995),
       (B) _rubrimaculatus_ (KU 58911), (C) _dennisi_ sp. nov. (holotype,
       UMMZ 101121), (D) _guttilatus_ (UIMNH 55520), (E) _marnockii_
       (TCWC 4782), and (F) _longipes_ (TCWC 12179). All ×6.5.]


    [Illustration: FIG. 2: Palmar views of hands of two species of the
       western complex of _Syrrhophus_. _pipilans_ (left, KU 58908, ×6)
       and _teretistes_ (center, KU 75269, and right, KU 75263,
       respectively, ×9).]


In _S. cystignathoides_ and _leprus_, the first finger is longer than
the second, and the first two fingers are equal in length in
_guttilatus_ and _marnockii_. In the other species the first finger is
shorter than the second.

Supernumerary tubercles are well developed on the plantar surfaces in
all species, except _S. guttilatus_, in which they are poorly defined
(Fig. 3). The relative sizes of the metatarsal tubercles has been used
in the classification of the species and species groups of _Syrrhophus_.
The metatarsal tubercles are similar in all species of the eastern
complex (including _rubrimaculatus_); the outer tubercle is always about
one-half the size of the ovoid inner metatarsal tubercle. In the
_leprus_ group the outer tubercle is conical and compressed. The
metatarsal tubercles of _pipilans_ are about the same size, or the outer
is slightly smaller than the inner. In the _modestus_ group the outer
metatarsal tubercle is about one-third the size of the inner.

All species, except _guttilatus_, have well-defined to poorly defined
lateral fringes on the toes. All species have expanded toe pads. The
fifth toe is usually shorter than the third, but the second is equal
in length to the fifth in some specimens of _S. cystignathoides_ and
_S. marnockii_. _Syrrhophus nivocolimae_ is the only species with
tubercles along the outer edge of the tarsus; this is merely a
reflection of the highly tuberculate nature of the skin in this species.


_Skin texture._--The skin of the dorsum is smooth or very weakly
pustular in all species of the genus except _nivocolimae_ and
_verrucipes_. The dorsal surfaces of _nivocolimae_ are warty; in
_verrucipes_ the skin is pustular. The skin of the venter is areolate in
_cystignathoides cystignathoides_, _dennisi_ and _verrucipes_ but is
smooth in all other species of the genus.

    [Illustration: FIG. 3: Plantar views of feet of four species of the
       eastern complex of _Syrrhophus_. (A) _guttilatus_ (UIMNH 55519, ×6),
       (B) _leprus_ (UIMNH 42726, ×6), (C) _verrucipes_ (UIMNH 15995, ×6),
       and (D) _longipes_ (TCWC 12179, ×4.6).]


_Color pattern._--As is evident in the diagnoses, the color patterns of
given populations have been regarded as useful in separating the
species and subspecies. Duellman (1958) suggested that the coloration,
with the exception of _modestus_, was a dark ground color with pale
markings. It is a moot point whether the frogs have light spots on a
dark background or have a light background with an extensive reticulate
dark pattern. The venters are gray or white, and the vocal sac is nearly
black in some species. Interorbital dark bars or triangles are absent in
only two species of the eastern complex, _cystignathoides campi_ and
_marnockii_; the latter lacks a supratympanic stripe, which is present
in the other members of the eastern complex. _Syrrhophus interorbitalis_
and _nivocolimae_ have light interorbital bars; these bars occur in only
one other population of the genus (_S. c. cystignathoides_). Bars on the
thighs are ill defined or absent in the members of the _marnockii_ and
part of the _modestus_ groups. The color in life is noted in the species
accounts.


_Voice._--The voices of all _Syrrhophus_ can be described as a
single short chirp or peep; without audiospectrographic analyses
the significance of the differences between a chirp, peep, or short
whistle cannot be appreciated. Martin (1958) and Wright and
Wright (1949) reported multi-noted calls, and one collector of
_S. verrucipes_ noted the frog "trilled."

Fouquette (1960) presented analyses of two species (_marnockii_
and _pipilans nebulosus_). The voices were very similar; both frogs
were reported to "trill" and "chirp."




SYSTEMATIC ACCOUNT


The genus _Syrrhophus_ has been defined (Lynch, 1968) and limited to the
group of species occurring in Guatemala, México and the United States.
The closest relatives of _Syrrhophus_ are the frogs of the genus
_Tomodactylus_ (Dixon, 1957; Firschein, 1954). Lynch (1968)
implied there were no osteological bases for the separation of
_Eleutherodactylus_, _Syrrhophus_, and _Tomodactylus_. At that time, I
believed such to be the case and derived _Syrrhophus_ and _Tomodactylus_
from the _rhodopis_ complex of _Eleutherodactylus_, with which they
share terrestrial habits and relatively short limbs. In the _rhodopis_
complex there is a tendency for the loss of the outer palmar tubercle, a
not uncommon condition in _Syrrhophus_ and _Tomodactylus_.

However, the skulls of _Syrrhophus_ and _Tomodactylus_ show departures
from the pattern observed in the Middle American _Eleutherodactylus_, as
well as many of those species in western South America. Baldauf and
Tanzer (1965) reported that the frontoparietals and prootics were fused
in _Syrrhophus marnockii_ and that the prootics and exoccipitals
appeared to be one bone (otoccipital). The otoccipital is not uncommon
in eleutherodactyline frogs, but the fusion of the frontoparietals with
the prootics (regardless of the fusion of the latter with the
exoccipital) is uncommon in the family. I have found the
frontoparietal-prootic fusion only in _Syrrhophus_ (all species),
_Tomodactylus_ (all species), and _Eleutherodactylus_ (West Indies
species). None of the Middle American _Eleutherodactylus_ has the two
bones fused. Examination of the character is difficult in dried skeletal
preparations. Cleared and stained or macerated preparations are
satisfactory for checking this character.

Thus, in addition to the presence of numerous plantar supernumerary
tubercles in the frogs of the genera _Syrrhophus_ and _Tomodactylus_,
these two genera can be separated from other Middle American
eleutherodactylines by the fusion of the frontoparietals and prootics.
This character not only further strengthens the argument that the two
genera are closely related but poses a problem of zoogeographic analysis
of the distribution of the character, which will be discussed fully
elsewhere.


Key to the Species of the Frog Genus _Syrrhophus_

  1. Three large, well-developed palmar tubercles                         2

     Two large palmar tubercles; outer (third) palmar tubercle reduced
     in size or absent                                                    9

  2. Digital pads more than twice (usually three or more) times width
     of digit                                                             3

     Digital pads less than twice width of digit                          4

  3. Males having vocal slits; dorsum vermiculate; diameter of
     tympanum in males about one-half diameter of eye          _S. dennisi_

     Males lacking vocal slits; dorsum flecked, spotted, or
     blotched; diameter of tympanum in male about three-fourths
     that of eye                                              _S. longipes_

  4. First finger longer than second                                      5

     First finger shorter than or equal to second                         7

  5. Venter smooth; dorsum spotted or vermiculate               _S. leprus_

     Venter areolate, or if smooth, dorsum flecked and interorbital
     bar lacking                                                          6

  6. Venter areolate; interorbital bar present; ground color
     yellowish                         _S. cystignathoides cystignathoides_

     Venter smooth; interorbital bar absent; ground color
     brown                                       _S. cystignathoides campi_

  7. First finger shorter than second; digital tips only slightly
     dilated; green in life with darker green spots         _S. verrucipes_

     First finger equal to second; digital tips slightly to moderately
     expanded                                                             8

  8. Dorsum vermiculate; interorbital bar present; ground color
     cream to brown in life                                 _S. guttilatus_

     Dorsum punctate or flecked; interorbital bar absent;
     ground color green in life                              _S. marnockii_

  9. Dorsum dark with pale (red in life) spots; digital pads
     not expanded                                       _S. rubrimaculatus_

     Dorsum pale with dark markings and digital pads slightly to widely
     expanded                                                            10

 10. Digital tips not widely expanded; tympanum well-defined;
     outer metatarsal tubercle more than one-half size of inner          11

     Digital tips widely expanded, truncate in outline; tympanum
     poorly defined; outer metatarsal tubercle less than one-half
     size of inner                                                       12

 11. Dorsum dark brown with large light spots or blotches; tympanum/eye
     ratio usually greater than 43 percent           _S. pipilans pipilans_

     Dorsum dark brown with small light spots; tympanum/eye
     ratio less than 48 percent                     _S. pipilans nebulosus_

 12. Light interorbital bar present                                      13

     Light interorbital bar absent                                       14

 13. Adults small, less than 22 mm. snout-vent length with a
     broad mid-dorsal stripe; dark bands on shank narrower than
     light interspaces                                     _S. nivocolimae_

     Adults larger, more than 22 mm. snout-vent length; dorsum
     vermiculate; dark bands on shank broader than light
     interspaces                                        _S. interorbitalis_

 14. Dorsum spotted with discrete black spots; pattern
     definite                                                 _S. modestus_

     Dorsum reticulate or vermiculate, pattern poorly defined            15

 15. Adults small, less than 21 mm. snout-vent length; upper arm
     not banded                                               _S. pallidus_

     Adults larger, usually greater than 21 mm. snout-vent length;
     upper arm banded                                       _S. teretistes_




SPECIES ACCOUNTS


The following accounts do not include complete descriptions of each
taxon, because a more than adequate number of descriptions is available
in the recent (1940-1966) literature. An abbreviated synonymy, in which
are listed all combinations and emendations of names and significant
contributions to our knowledge of the taxon, is given for each. For each
species and subspecies the following are given: descriptive diagnosis,
statement of range, remarks on taxonomy, list of specimens examined,
illustration of color pattern, and distribution map.


=Syrrhophus cystignathoides= (Cope)

     _Phyllobates cystignathoides_ Cope, 1877:89-90
        [Syntypes.--Originally USNM 32402-32409, (32405 now in MCZ)
        from Potrero, near Córdoba, Veracruz, México, Francis Sumichrast
        collector.]

_Diagnosis._--Adults small, males 16.0 to 23.5 mm. in snout-vent length,
females 16.0-25.8 mm. in snout-vent length; vocal slits present in
males; finger tips slightly expanded; first finger longer than second;
outer metatarsal tubercle one-half size of inner, conical, compressed;
skin of dorsum weakly pustular, that of venter smooth to areolate;
tympanum 44 to 69 per cent diameter of eye (mean 55.5 per cent); ground
color yellow to brown in life with brown to black fleckings on dorsum
and flanks; limbs banded; interorbital bar present or not.

_Remarks._--Two geographic races (subspecies) are herein recognized;
previously these were held by various authors to be species (_campi_ and
_cystignathoides_). Intergradation occurs in southern Tamaulipas and
eastern San Luis Potosí, México. The two subspecies can be distinguished
on the basis of color pattern and the condition of the skin of the
venter.

_Distribution._--Low to moderate elevations from the Río Grande
embayment to central Veracruz, México (Fig. 5).


=Syrrhophus cystignathoides campi= Stejneger, New combination

     _Syrrhophus campi_ Stejneger, 1915:131-32. [Holotype.--USNM 52290,
        from Brownsville, Cameron Co., Texas; R. D. Camp collector,
        March 31, 1915]. Smith and Taylor, 1948:52. Martin, 1958:50.

_Diagnosis._--Venter smooth; usually no interorbital light and dark bars
present; ground color brown in life (Fig. 4a).

_Remarks._--Martin (1958) was the first author to point out
that _S. campi_ was probably a subspecies of the more southern
_S. cystignathoides_. Various references in the literature might lead
one to believe that the two were sympatric over much of northeastern
México; this error was created by the use of a single character
(condition of the skin of the venter) to characterize the two
populations. Specimens from southern Texas have a smooth venter, lack
interorbital bars and have, in general, a brown ground color, whereas
specimens from central Veracruz have an areolate venter, interorbital
light and dark bars and a yellow ground color. In southern Tamaulipas
and eastern San Luis Potosí, these characters vary discordantly, thereby
strongly suggesting that the two populations intergrade. Both
populations agree in other morphological characters; therefore, they are
here treated as geographic variants.

_Etymology._--Named for the collector of the type specimens, Mr. R. D.
Camp of Brownsville, Texas.

_Distribution._--Lower Río Grande embayment in Texas to central Nuevo
León and Tamaulipas, México. Intergrades are known from southern
Tamaulipas and adjacent San Luis Potosí, México (Fig. 5).

_Specimens examined._--(113) TEXAS, Cameron Co.: MCZ 10277-85, 10286
(10); Brownsville, AMNH 3215, 3218-20, 3221 (3), 5376, 62117, FMNH
105336, KU 8135-39, MCZ 3738-42, 3743 (10), TCWC 5908, 7139, TNHC 92-94,
20909, UMMZ 51760, 54031 (5), USNM 52290 (holotype); 22 mi. SE
Brownsville, TNMC 14223; 8 mi. SW Brownsville, UMMZ 101127 (3);
Harlingen, AMNH 62118, UMMZ 105200-205, 105206 (5), 105207 (4). _Hidalgo
Co._: Bentsen-Río Grande State Park, UMMZ 114378; 6 mi. S McAllen, TNHC
7136-39; Santa Ana Refuge, TCWC 13495-96; Weslaco, TCWC 17658-60.

MEXICO, _Nuevo León_: Salto Cola de Caballo, AMNH 57953-54, FMNH
30644-45, 37169-70; Monterrey, UIMNH 13324; 40 km. SE Monterrey, UIMNH
3686. _Tamaulipas_: 80 km. Matamoros, FMNH 27150 (13).

Intergrades [_S. c. cystignathoides_ × _S. c. campi_ (88)] MÉXICO, _San
Luis Potosí_: 5 km. E Ciudad del Maiz, UMMZ 106435; 16 km. W Naranjo,
FMNH 104584; Salto de Agua, 34 km. WSW Antigua Morelos, TCWC 6980.
_Tamaulipas_: 5 km. W Acuña, 1060 m., UMMZ 101172, 101173 (16),
101174-76, 101177 (6); 14.5 km. NNW Chamal, 430 m., UMMZ 111337 (2); 20
km. NNW Chamal, 700 m., UMMZ 111338 (11); 8 km. N Gómez Farías, 450 m.,
UMMZ 101165; 8 km. NE Gómez Farías, Pano Ayuctle, UMMZ 102264, 102924
(6); 8 km. NW Gómez Farías, 1060 m., LSUMZ 11084, UMMZ 101199, 102928
(5), 102929-32, 110124 (3); Río Guayala, near Magiscatzin, MCZ 24138-42,
85071-81, UMMZ 88242 (2); Magiscatzin, TCWC 6981; Las Yucas, north of
Aldama, MCZ 29665-68; 16 km. NE Zamorina, UMMZ 101124.

    [Illustration: FIG. 4: _Syrrhophus cystignathoides campi_
       (left, TCWC 13490) and _S. c. cystignathoides_ (right, KU 105500).
       Dorsal views ×2, sides of heads ×3.]


=Syrrhophus cystignathoides cystignathoides= (Cope), New combination

     _Phyllobates cystignathoides_ Cope, 1877:89-90 [Syntypes.--USNM
        32402-32409, from Potrero, near Córdoba, Veracruz, México,
        collected by Francis Sumichrast]. Boulenger, 1882:196.

     _Syrrhophus cystignathoides_: Cope, 1879:268. Kellogg, 1932:
        126-27. Taylor and Smith, 1945: 582-83. Smith and Taylor, 1948:50.
        Martin, 1958:49.

     _Syrrhaphus cystignathoides_: Günther, 1900:218.

     _Syrraphus cystignathoides_: Díaz de León, 1904:10.

     _Syrrhopus cystignathoides_: Barbour and Loveridge, 1946:170.

    [Illustration: FIG. 5: Distribution of _Syrrhophus cystignathoides
       campi_ (solid symbols) and the nominate subspecies (open symbols).]

_Diagnosis._--Venter areolate; interorbital light and dark bars present;
ground color yellow to brownish-yellow in life (Fig. 4b).

_Remarks._--Firschein (1954) briefly considered the status of Peters'
(1871) _Phyllobates verruculatus_ and noted that if it was a
_Syrrhophus_ it would probably be referrable to _S. cystignathoides_.
Peters' (1871) original description corresponds well with
_S. cystignathoides_, and the type-locality ("Huanusco" = Huatusco) is
within the range of that species. Firschein (1954) expressed doubt that
_verruculatus_ was a _Syrrhophus_, because Peters placed it in another
genus. However, Peters described _verruculatus_ a decade before Cope
diagnosed the genus Syrrhophus. Most frogs now called _Syrrhophus_, plus
a number of lower Central American frogs now placed in a variety of
genera were placed in _Phyllobates_ by Boulenger, Cope, and Peters.

The types of _Phyllobates verruculatus_ were destroyed during World War
II (Günther Peters, _in litt._); the specimens subsequently assigned to
the taxon by Kellogg (1932) are _Syrrhophus cystignathoides_. Because
the type specimens are lost and because the name antedates the more
established name, _cystignathoides_, I favor retaining _Phyllobates
verruculatus_ Peters as a _nomen dubium_.

Smith and Taylor (1948) reported _S. verruculatus_ from Tianguistengo,
Hidalgo, México. These specimens are examples of _verrucipes_. Smith
(1947) reported a specimen of _verruculatus_ from San Lorenzo, Veracruz.
Firschein (1954) referred it to _cystignathoides_, and Duellman (1960)
concluded that both authors were in error and that the specimen (USNM
123530) was a _leprus_.

_Etymology._--The trivial name is the diminutive of _Cystignathus_, a
once-used generic name for several leptodactylid frogs.

_Distribution._--Low and moderate elevations in the foothills along the
Sierra Madre Oriental from eastern San Luis Potosí to Central Veracruz,
México (Fig. 5).

_Specimens examined._--(130), MÉXICO, _Puebla_: Necaxa, UMMZ 69519-20.
_San Luis Potosí_: 5 km. W Aguismón, LSUMZ 4962-63; along Río Axtla,
road to Xilitla, UMMZ 105500; Tamazunchale, UIMNH 3199; 6.5 km. N
Tamazunchale, UMMZ 104039; 8 km. N Tamazunchale, UMMZ 119490.
_Veracruz_: Coatepec, 1210 m., FMNH 704966-67; 11 km. SE Coatepec, 850
m., FMNH 70468-70; below Córdoba, FMNH 104588, UIMNH 13321; Cuautlapam,
1000 m., FMNH 106477-80, KU 100364, UIMNH 58200-03, UMMZ 105392; Fortín
de las Flores, UIMNH 13322, 13339; 1.6 km. N Fortín de las Flores, UIMNH
42799-808, UMMZ 105389; 3.2 km. N Fortín de las Flores, UIMNH 26633-35;
4.8 km. N Fortín de las Flores, UIMNH 71967-68; 3.2 km. W Fortín de las
Flores (Barranca Metlac), 910 m., UIMNH 49294-95, UMMZ 115444-46,
118221, 119893 (2); Huatusco, KU 100363; Jalapa, 1400 m., FMNH 70440,
70443-51, 70454-65; 16 km. NE Jalapa, 1300 m., FMNH 70452-53; 8 km. E
Jalapa, UIMNH 13338; 9.5 km. S Jalapa, UMMZ 122083 (2); Mirador, KU
23967; Paraja Nuevo, El Suchil, UMMZ 85490 (7), 85491 (2), 90315; La
Passa, UIMNH 49293, 49297; 1 km. E Plan del Río, 240 m., UMMZ 102067
(2); Potrero Viejo, FMNH 104583, 104586, 105326-27, KU 26789, 100357-62,
UIMNH 13323, 13340-43; USNM 32402 (lectotype), 32403-04, 32406-09; 9.6
km. S Santa Rosa, TCWC 12785; 24 km. NE Tezuitlán (Puebla), UMMZ 105388;
Teocelo, FMNH 70437-38, KU 26080, 26790; 3.2 km. N Teocelo, FMNH 70439,
70441-42; 9.6 km. NW Tihuatlán, UIMNH 3684-85; 15 km. ENE Tlacotepec, KU
23966; 26 km. NW Tuxpan, UMMZ 126419.


=Syrrhophus leprus= Cope

     _Syrrhophus leprus_ Cope, 1879:268-69 [Holotype.--USNM 10040, from
        Santa Efigena, Oaxaca, México, Francis Sumichrast collector].
        Kellogg, 1932:124-5, 128. Taylor and Smith, 1945:582. Smith and
        Taylor, 1948:50-51. Duellman, 1958:8, pl. 1, Fig. 2; 1960:56-57.
        Gorham, 1966:165.

     _Syrrhaphus leprus_: Günther, 1900:217.

     _Syrrhophus leprus leprus_: Neill, 1965:85-86.

     _Syrrhophus leprus cholorum_ Neill, 1965:85-86 [Holotype.--Wilfred
        T. Neill collection 1525, from 3.9 mi. N San Antonio, Toledo
        District, British Honduras, collected October 28, 1959, by
        R. A. Allen, T. C. Allen, and W. T. Neill].

_Diagnosis._--Medium-sized frogs, males 20.5-26.5 mm. in snout-vent,
females 22.0-29.3 mm. in snout-vent length; vocal slits present in
males; tips of fingers dilated slightly; first finger longer than
second; inner metatarsal tubercle twice size of small, conical outer
metatarsal tubercle; skin of dorsum pustular, that of venter smooth;
snout subacuminate; diameter of tympanum 47.5-62.5 per cent of eye in
males, 38.6-57.9 per cent in females; dorsum yellowish-green with
chocolate brown blotches or spots forming reticulations in most
specimens; venter white to gray; flanks brown, spotted with white or
not; limbs banded; interorbital bar obscured by dorsal pattern.

    [Illustration: FIG. 6: Dorsal views of _Syrrhophus leprus_ showing
       variation in dorsal pattern (left, UMMZ 121244, ×2; right, KU 26106,
       ×1.7). Side of head (UIMNH 42726, ×7).]

    [Illustration: FIG. 7: Distribution of three species of eastern
       complex _Syrrhophus_: _leprus_ (circles), _rubrimaculatus_
       (triangles), and _verrucipes_ (squares).]

_Remarks._--My distribution map (Fig. 7) differs somewhat from that of
Duellman (1958), who was unaware of specimens reported by Taylor and
Smith (1945) from central Veracruz, México.

Duellman (1958, 1960) regarded _S. leprus_ as having a gray venter.
Neill (1965) characterized his new subspecies on the basis of white
venter and spots on the dorsum. Some specimens from throughout the range
have only small round spots, instead of vermiculations (Fig. 6). The
gray ventral coloration is largely restricted to the population in Los
Tuxtlas, Veracruz, but only about 80 per cent of the specimens from the
Los Tuxtlas have gray venters, whereas specimens from Guatemala, Oaxaca,
Tabasco, and central Veracruz, México, have white venters (rarely gray).
Since the specimens from British Honduras are not distinct from
specimens throughout most of the range, there is no reason to recognize
them as a subspecies.

_Etymology._--Greek, _lepra_, leprosy, in reference to the mottled color
pattern.

_Distribution._--Discontinuous; central Veracruz to British Honduras to
low elevations in the foothills of the Sierra Madre Oriental, Los
Tuxtlas, Sierra Madre de Chiapas (Isthmus of Tehuantepec (Fig. 7)).

_Specimens examined._--(84). GUATEMALA, _Alta Verapaz_: Chinajá, KU
55961-62. _El Petén_: 15 km. NW Chinajá, KU 55963; Piedras Negras, USNM
114085-92; Tikal, UMMZ 117035; Uaxactún, AMNH 55121-22.

MÉXICO, _Oaxaca_: Cerro San Pedro del Isthmo, UIMNH 35510; Finca La
Gloria, USNM 114093; 30.5 km. N Matías Romero, UIMNH 39459, 71969; Santa
Efigenia, USNM 10040 (holotype). _Tabasco_: Teapa, UMMZ 113799-800; 13.5
km. W Teapa, UMMZ 120253. _Veracruz_: 27.5 km. N Acayucan, UIMNH 42726;
Atoyac, UIMNH 13331, 49296; 3.2 km. N Catemaco, UIMNH 71976-77; Coyame,
UIMNH 38995, 38998, 40342; Dos Amates, TCWC 21211; Fortín de Las Flores,
FMNH 113751, 113753; Paraja Nuevo, El Suchil, UMMZ 90315; Potrero Viejo,
FMNH 113743-50, 126114-18, KU 26104-06, UIMNH 13332-37, UMMZ 88837; San
Andrés Tuxtla, UIMNH 27123-31, 28611, 71975, UMMZ 115450 (5); San
Lorenzo, USNM 123530; 4.5 km. NW Santiago Tuxtla, JDL 992 (skeleton),
UIMNH 27122; 32 km. S Sayula, EAL 1696; Tepalapan, 1.6 km. S Catemaco,
UMMZ 118222 (2); Volcán San Martín, south slope, UMMZ 118223; Volcán San
Martín, Rancho El Tular, UIMNH 35399-400, 40340-41.


=Syrrhophus rubrimaculatus= Taylor and Smith

     _Syrrhophus rubrimaculatus_ Taylor and Smith, 1945:583-85
        [Holotype.--USNM 114070, from La Esperanza, near Escuintla,
        Chiapas, México, collected May 13, 1940, by H. M. and R. Smith].
        Duellman, 1958:1-4, 7, 12, 14. Gorham, 1966:167.

     _Syrrhophus rubrimaculata_: Smith and Taylor, 1948:48-49.

    [Illustration: FIG. 8: _Syrrhophus rubrimaculatus_ (upper right,
       KU 58911, ×1.6; lower right, KU 58910, ×4) and _S. verrucipes_
       (upper left, UIMNH 15995, ×1.6; lower left, UIMNH 15989, ×3.7).]

_Diagnosis._--Small frogs, males 18.2-23.5 mm. snout-vent, females
19.0-22.5 mm. snout-vent length (small sample); vocal slits in males;
digital tips scarcely expanded (Fig. 1); first finger shorter than
second; outer palmar tubercle reduced in size; inner metatarsal tubercle
elongate, twice the size of small, conical outer metatarsal tubercle;
diameter of tympanum 35.5-46.5 per cent that of eye in both sexes;
dorsum brown with small pale spots (red in life); venter gray.

_Remarks._--Previous authors who treated _Syrrhophus_ placed this
species in the western complex, because it occurs on the Pacific versant
and has a reduced outer palmar tubercle. Duellman (1958) placed
_rubrimaculatus_ apart from the other western species, because of its
relatively unexpanded digital tips and coloration. The digital tips are
like those in _leprus_, which _rubrimaculatus_ resembles. Except for the
reduction of the outer palmar tubercle, _rubrimaculatus_ could be a
member of the _leprus_ group.

_Syrrhophus rubrimaculatus_ is probably best treated as a Pacific
derivative of the _leprus_ group, even though the palmar tubercles do
not agree. The removal of _rubrimaculatus_ from the western complex
results in a more homogeneous remainder and does not greatly increase
the heterogeneity of the eastern complex.

_Etymology._--Latin, meaning spotted with red; in reference to the
colors in life.

_Distribution._--Low to moderate elevations on the Pacific versant of
southeastern Chiapas, México (Fig. 7); probably extending into
adjacent Guatemala.

_Specimens examined._--(48) MÉXICO, _Chiapas_: Escuintla, UMMZ 88283; 6
km. NE Escuintla, UMMZ 87876-80; La Esperanza, UIMNH 13285, UMMZ
88496-97, USNM 114070 (holotype), 114054-69, 114072; Monte Cristo, UMMZ
88353; 1.3 km. N Puerto Madero, KU 58910-11; Finca San Jerónimo, 600-650
m., UIMNH 55299-312, 55313-16 (cleared and stained).


=Syrrhophus guttilatus= (Cope)

     _Malachylodes guttilatus_ Cope, 1879:264 [Holotype.--USNM 9888,
        from Guanajuato, Guanajuato, México; collected in 1877 by
        Alfredo Duges].

     _Syrrhopus guttulatus_: Boulenger, 1888:204-06.

     _Syrrhaphus guttulatus_: Günther, 1900:317.

     _Syrraphus guttulatus_: Díaz de León, 1904:11.

     _Syrrhophus guttilatus_: Nieden, 1923:399-400. Kellogg, 1932:125,
        127-28. Smith and Taylor, 1948:49, 51. Firschein, 1954:52-54.
        Gorham, 1966:164.

     _Syrrhophus smithi_ Taylor, 1940b:43-45, pl. 1 [Holotype.--USNM
        108594, from 15 mi. SW Galeana, Nuevo León, México, 1575 m.;
        collected on October 13, 1939, by Hobart M. Smith]. Smith and
        Taylor, 1948:49, 51. Firschein, 1954:54-55. Martin, 1958:50.
        Gorham, 1966:167.

     _Syrrhophus gaigeae_ Schmidt and Smith, 1944:80 [Holotype.--FMNH
        27361, from the Basin, Chisos Mountains, Brewster Co., Texas;
        collected on July 24, 1937, by Walter L. Necker].

     _Syrrhophus petrophilus_ Firschein, 1954:50-52 [Holotype.--UIMNH
        7807, from 5 km. SW San Luis Potosí, San Luis Potosí, México;
        collected on July 18, 1949, by David Langebartel]. Gorham,
        1966:166.

     _Syrrhophus marnocki_: Milstead, Mecham, and McClintock, 1950:548
        (in part).

_Diagnosis._--Medium-sized frogs, males 20.6-29.0 mm. snout-vent,
females 25.7-31.0 mm. snout-vent length; vocal slits in males; digital
tips slightly expanded (Fig. 1); first and second fingers equal; skin of
dorsum smooth to moderately pustular, that of venter smooth; snout
blunt; diameter of tympanum 55.1-75.7 per cent that of eye in males,
47.6-61.7 in females; dorsum and flanks cream to gray with light brown
to black flecking and vermiculations; thighs usually not banded;
interorbital bar present (Fig. 8).

    [Illustration: FIG. 9: _Syrrhophus guttilatus_ (upper left, UIMNH
       55519, ×1.4; lower left, UIMNH 55519, ×2.3) and _S. marnockii_
       (upper right, TCWC 9317, ×1.4; lower right, TCWC 13510, ×2.1).]

_Remarks._--Cope (1879) distinguished _Malachylodes_ from _Syrrhophus_
on the basis of the presence of a frontoparietal fontanelle in the
holotype of _guttilatus_. The holotype is a juvenile female and as is
the case in the juveniles of nearly all leptodactylids, a frontoparietal
fontanelle is present. Firschein (1954) used the presence of the
fontanelle to distinguish _guttilatus_ from his _petrophilus_.

As is clearly evident from the length of the synonymy, I consider a
number of currently used names to be synonymous with _guttilatus_. I
have seen the holotypes of all four names and am unable to recognize
more than a single species. The holotype of _petrophilus_ is a male,
whereas that of _smithi_ is a female. The supposed differences are a
reflection of sexual dimorphism in the size of the eye (Table 5). The
two holotypes, as well as those of _gaigeae_ and _Malachylodes
guttilatus_ agree in color pattern.

Schmidt and Smith (1944) named _Syrrhophus gaigeae_ from the Chisos
Mountains of the Big Bend region of Texas and compared it only with
_S. marnockii_. Milstead, Mecham and McClintock (1950) synonymized
_gaigeae_ and _marnockii_ because they were unable to verify the
characters Wright and Wright (1949) used to separate them. Specimens
from the Big Bend region differ from those of the Edward and Stockton
Plateaus in having a vermiculate pattern, an interorbital bar, and a
supratympanic stripe. In these respects they agree with specimens from
northern México. Based on limited observations, the Mexican population
is yellowish to brownish in life whereas the central Texas population is
green in life. Lacking evidence of genetic exchange, the two are held to
be specifically distinct.

Nearly every specimen examined was infested with chiggers of the genus
_Hannemania_. The greatest concentrations are on the venter, in the
groin, and on the thighs. Many specimens have chiggers on the digits and
tarsi. The same, or a related, chigger was found on many specimens of
_Syrrhophus marnockii_ and a few _S. verrucipes_, but on no other
species of the genus. Mr. Willy Wrenn told me that he has seen heavy
infestations of _Hannemania_ on _Syrrhophus pallidus_. Infestation by
_Hannemania_ probably reflects similar ecologies rather than close
relationships.

    [Illustration: FIG. 10: Distribution of _Syrrhophus guttilatus_.]

_Etymology._--Latin, _guttula_, meaning spotting or flecking, in
reference to the color pattern.

_Distribution._--Moderate to intermediate elevations (600 to 2000 m.)
along the Sierra Madre Oriental from the Big Bend Region of Texas to
Guanajuato, México (Fig. 10).

_Specimens examined._--(32) TEXAS, _Brewster Co._: Juniper Canyon,
Chisos Mts., FMNH 27361 (holotype of _S. gaigeae_), 27360, 27362-63, MCZ
15346, 27801, UMMZ 66080, 66082, 66085-91, USNM 76876; Upper Green
Gulch, TCWC 15943.

MÉXICO: _Coahuila_: 8 km. S Saltillo, UIMNH 55518-21. _Guanajuato_:
Guanajuato, USNM 9888 (holotype of _Malachulodes guttilatus_); 8 km. E
Guanajuato, AMNH 73425; Cerro Cubilete, AMNH 73424. _Nuevo León_: 3 km.
S Galeana, JDL 1215 (skeleton), UIMNH 58204; 24 km. SW Galeana. 1575 m.,
USNM 108594 (holotype of _Syrrhophus smithi_). _San Luis Potosí_: 5 km.
SW San Luis Potosí, UIMNH 7807 (holotype of _S. petrophilus_).
_Tamaulipas_: 1.6 km. NW La Joya de Salas, 1530 m., UMMZ 110736 (4).


=Syrrhophus marnockii= Cope

     _Syrrhophus marnockii_ Cope, 1878:253 [Syntypes.--ANSP 10765-68,
        from "near San Antonio," Bexar Co., Texas; collected by G. W.
        Marnock].

     _Syrrhophus marnocki_: Yarrow, 1882:24, 193. Milstead, Mecham,
        and McClintock, 1950:550.

_Diagnosis._--Medium-sized frogs, males 18.4-28.9 mm. snout-vent,
females 20.4-35.4 mm. snout-vent length; vocal slits in males; digital
tips widened (Fig. 1); first and second fingers equal; skin of dorsum
smooth to weakly pustular, that of venter smooth; snout blunt, rounded;
diameter of tympanum 47.2-68.3 per cent that of eye in males, 45.8-73.3
in females; dorsum tan to light brown in preservative with rusty-brown
flecks, venter white; ground color green in life; thighs banded;
interorbital bar absent.

_Remarks._--Specimens from the southern edge of the Edwards Plateau and
the eastern edge of the Stockton Plateau have larger flecks on the back
that tend to form a vermiculate pattern like that of _S. guttilatus_.
The vermiculation is never well developed (see plate 38 in Conant,
1958). Most of the specimens from the Edwards Plateau have a punctate
pattern (Fig. 9).

Fossils are known from the Sangamon interglacial deposits in Foard and
Knox Counties, Texas (Lynch, 1964; Tihen, 1960).

_Etymology._--A patronym for the collector of the type specimens.

_Distribution._--The Edwards Plateau and the extreme eastern edge of the
Stockton Plateau in Texas (Fig. 11). The fossil records lie some 200
miles to the north. Two specimens (FMNH 103216-17) from Brownsville,
Cameron Co., Texas, were formerly in the EHT-HMS collection (nos.
31348-49). Data given in Taylor's field catalogue (housed in the
Division of Reptiles, Field Museum) are "Brownsville, A. J. Kirn
collector, April 15, 1934." Until verification by recently collected
material is available, this record must be disregarded.

_Specimens examined._--(103) TEXAS, _Bandera Co._: 10 mi. SW Medina,
TCWC 13508-10; 8 mi. W Medina, KU 60243; 13 mi. W Medina, KU 60242, TCWC
13506-07. _Bexar Co._: UIMNH 34694; Classen ranch, near San Antonio.
UMMZ 98891; Helotes, EAL 1560, MCZ 11837 (2), UMMZ 64045, USNM 13635; 2
mi. N Helotes, TCWC 9234-35; 3.5 mi. N Helotes, LSUMZ 10363; 8 mi. N
Helotes, TCWC 1549, 4364; San Antonio, FMNH 15553-56, TCWC 13497-99.
_Blanco Co._: 8 mi. NE Blanco, TCWC 4782. _Comal Co._: New Braunfels,
TCWC 13500-05; 5 mi. NE New Braunfels, UMMZ 71016 (10). _Hays Co._: San
Marcos, AMNH 22661-64, 32700, FMNH 15245-46, 26250, 26253-57, 37617,
37665, MCZ 15649-50, 23268-69; 6 mi. SW San Marcos, TCWC 5070-71, 7140,
9232-33, 9236, 9316-17, 9320. _Kendall Co._: 11 mi. E Boerne, AMNH
54660-61, 54662 (2); 10 mi. W Boerne, KU 18441; Kendalia, UIMNH 21434.
_Kerr Co._: Kerr W. M. Area, TCWC 15859; 40 mi. NW Kerrville, TCWC 6555.
_Medina Co._: UIMNH 13287-88; 12 mi. N Castroville, UIMNH 21423; 14 mi.
N Castroville, UIMNH 21424-25; 16 mi. N Castroville, UIMNH 21421-22; 17
mi. N Castroville, UIMNH 21428-29; 18 mi. N Castroville, UIMNH 21426-27,
21430-33; 6.5 mi. NW Rio Medina, KU 18440. _Real Co._: Rio Frio, FMNH
55156-57. _Travis Co._: Austin, AMNH 44221-22; Mount Bonnell, 5 mi. S
Austin, UMMZ 101453 (10). _Uvalde Co._: 13 mi. from Uvalde, UIMNH 62322.
_Val-Verde Co._: 40 mi. N Del Rio, JDL 214 (skeleton).

    [Illustration: FIG. 11: Distribution of _Syrrhophus marnockii_
       (circles). Starred localities are late Pleistocene records.]


=Syrrhophus verrucipes= Cope

     _Syrrhophus verrucipes_ Cope, 1885:383 [Holotype.--ANSP 11325, from
        near Zacualtipán, Hidalgo, México (1800 feet lower in a rocky gorge
        of a stream near its junction with the Río San Miguel), collected
        by Dr. Santiago Bernard]. Kellogg, 1932:126-29. Smith and Taylor,
        1948:52-53. Firschein, 1954:55-57. Gorham, 1966:167.

     _Syrrhaphus verrucipes_: Günther, 1900:216-17.

     _Tomodactylus macrotympanum_ Taylor, 1940e:496-99, pl. 55,
        figs. 2a-b. [Holotype.--FMNH 100049 (formerly EHT-HMS 6838),
        from La Placita, 8 km. S Jacala, Hidalgo, México, 1850 m.;
        collected on July 2, 1936, by Edward H. Taylor]. Smith and
        Taylor, 1948:47-48.

     _Syrrhophus macrotympanum_: Dixon, 1957:384. Gorham, 1966:165.

_Diagnosis._--Medium-sized frogs, males 17.5-26.1 mm. snout-vent,
females 28.0-31.7 mm. snout-vent length; vocal slits in males; digital
tips slightly expanded; first finger shorter than second; skin of dorsum
pustular, that of venter areolate; snout elongate, subacuminate;
diameter of tympanum 56.1-76.7 per cent that of eye in males, 54.3-56.8
in females; in preservative, dorsum reddish brown with numerous small
black or dark brown spots (Fig. 8); venter white to cream; in life
dorsum green with darker green spots, belly white; iris gold above,
bronze below.

_Remarks._--Cope's (1885) original description was not sufficiently
clear to enable subsequent authors to recognize this species. Taylor
(1940e) described it as a _Tomodactylus_, but Dixon (1957) pointed out
that _T. macrotympanum_ differed from the other species of the genus in
having a poorly developed lumbo-inguinal (inguinal) gland, and placed
the species in the genus _Syrrhophus_. Comparison of the holotypes of
_S. verrucipes_ and _T. macrotympanum_ leaves no doubt in my mind that a
single species is involved. This same species was reported by Smith and
Taylor (1948) as _S. verruculatus_.

_Syrrhophus verrucipes_ bears resemblance to members of both the
_leprus_ and _marnockii_ groups. In snout shape it is closer to the
_leprus_ group, whereas in digital pad, the shape of the general body
form, and contiguity of habitat it is most similar to the _marnockii_
group (_S. guttilatus_).

_Etymology._--Latin, meaning warty foot, probably in reference to the
numerous plantar supernumerary tubercles.

_Distribution._--Moderate elevations in southeastern San Luis Potosí,
Queretaro, and northwestern Hidalgo, México (Fig. 7).

_Specimens examined_--(43) MÉXICO, _Hidalgo_: Jacala, UMMZ 106434; 9.6
km. NE Jacala, Puerto de la Zorra, 1820 m., KU 60240-41, TCWC 11090,
11147; 8 km. S Jacala, La Placita, 1850 m., FMNH 100049 (holotype of
_Tomodactylus macrotympanum_), 100791-803, 105334-35, 114287, UIMNH
15989-92, 15995-96, UMMZ 117252, USNM 137202; Tianguistengo, FMNH
113705-09, UIMNH 13328-30; near Zacualtipán, ANSP 11325 (holotype of
_Syrrhophus verrucipes_). _Queretaro_: 3.5 km. S San Juan del Río, EAL
1343. _San Luis Potosí_: 9.6 km. W Ahuacatlán, LSUMZ 4968-70.


=Syrrhophus dennisi= new species

     _Syrrhophus latodactylus_: Martin, 1958:49 (in part).

_Holotype._--UMMZ 101121, adult male from a cave near El Pachón, 8 km. N
Antiguo Morelos, Tamaulipas, México, 250 m., collected on March 13,
1949, by Paul S. Martin.

_Paratopotypes._--(26). UMMZ 101122 (10), 101123 (2), 101126, 126993
(12).

_Diagnosis._--Medium-sized frogs, males 22.8-28.4 mm. snout-vent,
females 25.9-32.0 mm. snout-vent; vocal slits in males; digital tips
greatly expanded, more than twice width of digit; first finger shorter
than second; skin of dorsum shagreened to pustular, that of venter
weakly to moderately areolate; toes webbed basally; dorsum light brown
to tan with brown vermiculations; venter white; diameter of tympanum
53.9 to 64.2 per cent that of eye in males, 50.6 to 58.7 per cent in
females.

_Description and variation._--(Fig. 12). Head wider than body; head as
wide or wider than long in males, sometimes longer than wide in females;
snout acuminate in dorsal view, elongate and rounded in lateral profile;
canthus rostralis rounded but distinct; loreal region slightly concave,
sloping abruptly to lip; lips not flared; eyelid about two-thirds
interorbital distance; length of eye less than distance between eye and
nostril; diameter of tympanum 53.9 to 64.2 per cent that of eye in
males, 50.6 to 58.7 per cent in females; tympanum round and distinct in
both sexes; supratympanic fold moderately distinct; choanae within
border of jaws, completely visible from directly below, rounded to
slightly oval; dentigerous processes of prevomers and teeth absent;
tongue free for posterior one-half, generally oval in outline; vocal
slits present in males.

Many scattered pustules on dorsum; flanks areolate; skin of venter
areolate or not (variability may be due to differences in preservation);
ventral disc distinct on chest and lower abdomen; inguinal gland present
or not, when present varying from very large and distinct to poorly
defined; axillary gland absent.

First finger shorter than second; all fingers bearing truncate tips with
pads, each pad having a terminal groove; fingers fringed; fingers three
and four having dilated pads two to three times width of digit;
subarticular tubercles large, conical, rounded, simple; supernumerary
tubercles numerous on thenar surface, none on digits; three palmar
tubercles, outer slightly smaller than largest supernumerary tubercles;
row of tubercles on outer edge of forearm variable, weak to very
distinct; tips of toes wider than digits, rounded to truncate at tips,
each pad having terminal groove; toes having lateral fringes, bases of
toes united by web, web not extending to basal subarticular tubercle;
subarticular tubercles smaller than those of hand, round, conical,
simple; supernumerary tubercles numerous on plantar surfaces, extending
between metatarsal tubercles, present on toes between basal two
subarticular tubercles in some specimens; outer metatarsal tubercle
round, conical, one-half as large as ovoid, non-compressed inner
metatarsal tubercle; tarsal tubercles or folds absent.

Ground color pale reddish-brown to tan dorsally, creamy on flanks;
dorsal pattern consisting of reddish-brown to brown vermiculations
extending onto flanks; distinct interorbital light bar present; loreal
region darker than snout, reddish-brown compared to tan or pale
reddish-brown; arms colored like dorsum; thighs banded, unicolor brown
on posterior surfaces; shanks and tarsi banded; venter white to cream
punctated with brown in some specimens.

The variation in proportions is summarized in Table 5.

_Remarks._--Martin (1958) expressed some doubt that this series of 26
specimens was identical with "_S. latodactylus_." My study indicates
that the specimens from El Pachón represent a distinctive but allied
species. Males of the two species can be readily separated by the
relative sizes of the tympani, presence or absence of vocal slits, and
color pattern. Females of the two species can be separated by color
pattern. Within the type-series, the pattern varies from weakly to
strongly vermiculate but is always recognizable as vermiculate rather
than spotted as in _S. longipes_ (= _S. latodactylus_ of Taylor and
Martin).

    [Illustration: FIG. 12: _Syrrhophus dennisi_ sp. nov., holotype,
       UMMZ 101121 (dorsum ×1.8, side of head ×6.1).]

_Etymology._--The specific name is a patronym for David M. Dennis, whose
drawings greatly enhance the worth of this paper.

_Distribution._--Known only from the type series.


=Syrrhophus longipes= (Baird), New combination

     _Batrachyla longipes_ Baird, 1859:35, pl. 37, fig. 1-3
        [Holotype.--apparently USNM 3237 (cited as 3207 by Cope, 1887:16),
        now lost, from 40 Leagues from (probably north) México City;
        collected by John Potts]. Kellogg, 1932:107.

     _Epirhexis longipes_: Cope, 1866:96.

     _Eleutherodactylus longipes_: Kellogg, 1932:107 (part). Smith and
        Taylor, 1948:61. Lynch, 1963:580-581. Gorham, 1966:82.

     _Syrrhophus latodactylus_ Taylor, 1940d:396-401, pl. 43, figs. A-F,
        text fig. 7 [Holotype.--FMNH 100063 (formerly EHT-HMS 6807), from
        Huasteca Canyon, 15 km. W Monterrey, Nuevo León, México, 680 m.;
        collected on June 20, 1936, by Edward H. Taylor]. Smith and
        Taylor, 1948:50-52. Martin, 1958:48-50. Gorham, 1966:165.

_Diagnosis._--Large frogs, males 22.1-33.2 mm. snout-vent, females
26.8-39.6 mm. snout-vent length; vocal slits lacking in males; digital
tips greatly expanded (more than twice the width of digit); first finger
shorter than second; skin of dorsum pustular, that of venter smooth;
diameter of tympanum in males 61.1-87.2 per cent that of eye, 49.5-72.1
per cent in females; dorsum tan with large or small spots and blotches;
limbs banded; interorbital bar or triangle present.

_Remarks._--I have applied Baird's _Batrachyla longipes_ to the frog
Taylor (1940d) called _Syrrhophus latodactylus_ because the color
pattern (Fig. 13) predominant in the southern part of the range agrees
with that described (figured) for _Batrachyla longipes_.

The color pattern of individuals in the southern part of the range of
this species consists of large spots or blotches, whereas in the
northwestern part the pattern is made up of smaller spots. In the
northeastern part of the range, the pattern is more reduced and tends to
consist of heavy flecking. The interorbital bar is narrower in specimens
from Nuevo León and Tamaulipas and is triangular in specimens from
Hidalgo and Queretaro.

The status of the name _Batrachyla longipes_ is currently that of a
_nomen dubium_ (Lynch, 1963). At that time, I was unaware of the
geographic variation in color pattern in _Syrrhophus latodactylus_.

The exact type-locality of _Batrachyla longipes_ is not known. If it is
40 Leagues north of México City, the locality would be in an area where
the species has a blotched instead of a flecked or spotted pattern. No
justifiable evidence was presented to place _Batrachyla longipes_ in
_Eleutherodactylus_ instead of _Syrrhophus_. Barbour (1923) and Kellogg
(1932) associated another species (_E. batrachylus_) with _longipes_.
Taylor (1940a) noted this as a case of misidentification and corrected
the error but left _longipes_ in the genus _Eleutherodactylus_. Lynch
(1963) noted several points of morphological agreement between
_Syrrhophus_ and _B. longipes_ but did not place _longipes_ in
_Syrrhophus_.

Baird's (1859) figures of the holotype do not illustrate prevomerine
teeth, but according to Cope (1866) they were present in the holotype.
The digital tips of the frog in the figure are somewhat narrower than
those typically seen in _S. latodactylus_. If the specimen was slightly
desiccated, as possibly was the case, the digits would appear narrower.
There is no evidence contrary to placing _Syrrhophus latodactylus_ in
the synonymy of _Batrachyla longipes_.

    [Illustration: FIG. 13: Dorsal views of _Syrrhophus longipes_
       illustrating geographic variation in pattern (left, TCWC 12179,
       ×1.5; right, KU 92572, ×1.8); side of head (TCWC 10966, ×6).]

Application of Baird's name _Batrachyla longipes_ to the species of frog
heretofore called _Syrrhophus latodactylus_ poses one serious problem.
_Batrachyla longipes_ is the type-species (by original designation) of
the genus _Epirhexis_ Cope, 1866, which has priority over _Syrrhophus_
Cope, 1878. If _Batrachyla longipes_ is left in the status of a _nomen
dubium_, _Epirhexis_ can be forgotten, for the two names are tied
together. However, since it seems almost certain that _Batrachyla
longipes_ and _Syrrhophus latodactylus_ are conspecific, the former name
should not be left as a _nomen dubium_. _Epirhexis_ never came into
general usage (Cope cited the name four times, but no one else has used
it), whereas _Syrrhophus_ is well established in the zoological
literature. It would serve only to confuse the literature to adhere
strictly to the Law of Priority and replace _Syrrhophus_ with
_Epirhexis_. Therefore, _Syrrhophus_ is used in this paper, even though
_Epirhexis_ has priority. A request for the suppression of _Epirhexis_
Cope, 1866, has been submitted to the International Commission of
Zoological Nomenclature (Lynch, 1967).

_Etymology._--Latin, meaning long-footed; Taylor's _latodactylus_ refers
to the wide digital pads.

    [Illustration: FIG. 14: Distribution of _Syrrhophus dennisi_
       (triangle) and _S. longipes_ (circles).]

_Distribution._--Moderate elevations (650 to 2000 meters) along the
Sierra Madre Oriental from central Nuevo León to northern Hidalgo,
México (Fig. 14).

_Specimens examined._--(122) MÉXICO, _Hidalgo_: 3 km. NE Jacala, AMNH
52977; 9.6 km. NE Jacala, 1800 m., TCWC 10966-70, 12179; 8 km. S Jacala,
La Placita, 1850 m., FMNH 100266-68, 103244, UIMNH 13291, 13327. _Nuevo
León_: Salto Cola de Caballo, KU 92572; Huasteca Canyon, 15 km. W
Monterrey, 680 m., FMNH 100063 (holotype of _S. latodactylus_), UIMNH
13290; 6.5 km. N Pablillo, EAL 1319; Sabinas Hidalgo, USNM 139728.
_Queretaro_: Cueva de los Riscos, 8 km. SW Jalpan, KU 106300. _San Luis
Potosí_: 13 km. E Santa Barberita, LSUMZ 2295; second camp, San Luis
Potosí road, UIMNH 13326; Xilitla, Cueva sin nombre, UMMZ 125892.
_Tamaulipas_: 4 km. W El Carrizo, 500 m., UMMZ 111343 (31); 8 km. N
Chamal, Bee Cave, KU 106299; 14.5 km. NNW Chamal, 420 m., UMMZ
111339-40, 111342 (4), 111344 (11); 19 km. NNW Chamal, 700 m., UMMZ
111341 (3); El Chihue, 1880 m., UMMZ 111289 (4); 11 km. N Gómez Farías,
1060 m., UMMZ 101166; 11 km. WNW Gómez Farías, 1800 m., UMMZ 108507 (3);
8 km. NW Gómez Farías, 1060-1400 m., LSUMZ 11085, UMMZ 101167 (3),
101168 (4), 101169 (2), 101170 (3), 101171 (2), 101360-61, 102860,
102933 (4), 102934 (2), 102935-38, 102939 (2), 102940-43, 108800 (3),
110735, 111345-46.


=Syrrhophus pipilans= Taylor

     _Syrrhophus pipilans_ Taylor, 1940c:95-97, pl. 1 [Holotype.--FMNH
        100072 (formerly EHT-HMS 6843), 14.6 km. S Mazatlán, Guerrero,
        México; collected on July 22, 1936, by Edward H. Taylor].

_Diagnosis._--Medium sized frogs, males 22.6-28.5 mm. snout-vent,
females 21.1-29.4 mm. snout-vent length; vocal slits present in males;
finger tips slightly expanded, truncate in outline; inner metatarsal
tubercle less than twice the size of outer; skin of dorsum smooth to
shagreened, that of venter smooth; tympanum 36.5-54.0 per cent diameter
of eye; dorsum dark brown with large or small light brown, orange-brown,
or yellowish spots or blotches; limbs banded; interorbital bar absent.

    [Illustration: FIG. 15: Dicegrams of ear size relative to eye
       diameter in the two subspecies of _Syrrhophus pipilans_. N = 17
       in _nebulosus_, 18 in _pipilans_.]

_Remarks._--Two subspecies were recognized by Duellman (1958).
Previously both had been treated as species. The two populations were
distinguished on the basis of color pattern and the size of the
tympanum. Measurements of 17 males of _S. p. nebulosus_ from central
Chiapas and 18 males of _S. p. pipilans_ from southcentral Oaxaca and
Guerrero, México, demonstrates that the supposed difference in tympanum
size is not significant (Fig. 15). There is, however, a tendency for
the western population of _S. pipilans_ to have larger tympani. Based on
the present examination of 112 specimens of this species the two
populations are held to be sufficiently distinct to warrant taxonomic
recognition as subspecies (Fig. 16).

    [Illustration: FIG. 16: _Syrrhophus pipilans nebulosus_ (left,
       KU 58908) and _S. p. pipilans_ (right, KU 86885). ×2.7.]

The parotoid glands attributed to this species by Taylor (1940c:95) are
merely the superficial expression of the _m. depressor mandibulae_ and
scapula. No true glands are present in the parotoid region.


=Syrrhophus pipilans nebulosus= Taylor

     _Syrrhophus nebulosus_ Taylor, 1943:353-55, pl. 27, figs. 3-5
        [Holotype.--FMNH 100095 (formerly EHT-HMS 3774), near Tonolá,
        Chiapas, México; collected on August 27, 1935, by Hobart M.
        Smith and Edward H. Taylor]. Smith and Taylor, 1948:49, 51.

     _Syrrhophus pipilans nebulosus_: Duellman, 1958:2-4, 9, 12, 14.
        Stuart, 1963:32-33. Gorham, 1966:166-67.

_Diagnosis._--Diameter of tympanum 36.6-47.8 per cent that of eye;
dorsum dark brown with numerous small light brown to yellowish spots.

_Remarks._--The distribution of this subspecies is adequately described
by Duellman (1958). Fouquette (1960) described the vocalization of this
frog.

_Etymology._--Latin, _nebula_, in reference to the clouded dorsal
pattern.

_Distribution._--Low to moderate elevations along the Pacific versant of
Chiapas and in the Grijalva valley of Chiapas and Guatemala (Fig. 17).

_Specimens examined._--(54) GUATEMALA, _Huehuetenango_: Jacaltenango,
UMMZ 117036; 35 km. SE La Mesilla, TNHC 29652. MÉXICO, _Chiapas_: 11.2
km. N Arriaga, 300 m., UMMZ 125891; 11.8 km. N Arriaga, UMMZ 117279;
12.8 km. N Arriaga, UMMZ 117280; 17.5 km. S Arriaga, UIMNH 57108-109;
1.5 km. S Bochil, 1250 m., KU 58898-908; Cerro Hueco, 7 km. S Tuxtla
Gutierrez, UMMZ 123007; 3.2 km. S Ixtapa, UMMZ 124000; Linda Vista, ca.
2 km. NW Pueblo Nuevo Solistahuacán, KU 58897; Hda. Monserrate, 40 km.
NW Arriaga, UMMZ 102258; near San Ricardo, FMNH 100720; Tapachula, FMNH
75792, 103242, 100695-96, UIMNH 13292; 56 km. E Tapanatepec, Oaxaca,
TNHC 26942, Tonolá, FMNH 100095 (holotype), 100686-92, UIMNH 13293-95;
Tuxtla Gutierrez, FMNH 100693-94, UIMNH 13297; 19 km. N Tuxtla
Gutierrez, TNHC 25229-30; 15.5 km. NE Tuxtla Gutierrez, UMMZ 119892 (3);
19 km. NE Tuxtla Gutierrez, UMMZ 119891 (3); 8 km. NNW Tuxtla Gutierrez,
KU 37809; Unión de Juarez, FMNH 105294.


=Syrrhophus pipilans pipilans= Taylor

     _?Syrrhopus verruculatus_: Gadow, 1905:194.

     _Syrrhophus pipilans_ Taylor, 1940c:95-97, pl. 1 [Holotype.--FMNH
        100072 (formerly EHT-HMS 6843), from 14.6 km. S Mazatlán,
        Guerrero, México; collected on July 22, 1936, by Edward H. Taylor].
        Taylor and Smith, 1945:581-82. Smith and Taylor, 1948:49, 50-51.

     _Syrrhophus pipilans pipilans_: Duellman, 1958:1-4, 8-9, 13-14,
        pl. 2, fig. 1. Gorham, 1966:166.

_Diagnosis._--Diameter of tympanum 40.6-54.0 per cent that of eye;
dorsum dark brown with large light spots or blotches.

_Remarks._--Duellman's (1958) synopsis of this subspecies is adequate;
the distribution has not been extended, but several records are now
available which fill in gaps.

    [Illustration: FIG. 17: Distribution of _Syrrhophus pipilans_:
       _nebulosus_ (open circles) and _pipilans_ (solid circles).]

Gadow's (1905) record of _S. verruculatus_ from "Buena Vista, S.
Guerrero" is most likely applicable to this species. Gadow simply
included the name in a list of the species he had collected during his
trip in México (1902-04); no further comment was made on this species
although references to _Syrrhopus_ (sic) appear in several places in the
paper and would appear to apply to the species he had.

_Etymology._--Latin, _pipilo_, chirping, peeping, in reference to the
call of the male.

_Distribution._--Sea level to about 1800 meters along the Pacific
versant of western México from central Guerrero to the Isthmus of
Tehuantepec (Fig. 17).

_Specimens examined._--(62). MÉXICO, _Guerrero_: Acapulco, UMMZ 110125;
6.4 km. N Acapulco, FMNH 100389, 100525; Agua del Obispo, 980-1000 m.,
FMNH 75791, 100518-21, 100526, KU 86884-86, UIMNH 13315, UMMZ 119152,
125890 (4); 13.3 km. NW Coyuca, UIMNH 38367, 71982-83; 14.5 km. S
Mazatlán, FMNH 100072 (holotype), 100408, 100511-17, UIMNH 13302-309;
Tierra Colorado, 300 m., KU 67961, UIMNH 13313-14; near El Treinte, FMNH
126639; Xaltinanguis, FMNH 100522-24, 126640. _Oaxaca_: Cacahuatepec,
UIMNH 52853; 8 km. NW Río Canoa, 53 km. ESE Cuajinicuilapa, UIMNH
52852; 6.4 km. N El Candelaria, UIMNH 9501; 11.2 km. S El Candelaria,
UIMNH 9502; 17 km. NE Juchatengo, 1600 m., KU 86887; 31.5 km. N
Pochutla, UMMZ 123999 (2); 32.9 km. N Pochutla, 850 m., UMMZ 123996;
37.1 km. N Pochutla, UMMZ 123998 (2); 41.4 km. N Pochutla, UMMZ 123997
(2); Cerro Quiengola, FMNH 105653; 3.8 km. N Santiago Chivela, UMMZ
115449; 14.5 km. W Tehuantepec, UMMZ 115448 (2).


=Syrrhophus interorbitalis= Langebartel and Shannon

     _Syrrhophus interorbitalis_ Langebartel and Shannon, 1956: 161-65,
        figs. 1-2 [Holotype.--UIMNH 67061 (formerly FAS 9378), 36 mi. N
        Mazatlán, Sinaloa, México, collected on November 17, 1955, by
        E. C. Bay, J. C. Schaffner, and D. A. Langebartel]. Duellman,
        1958:1-4, 10, 12, 14. Gorham, 1966:164-65.

     _Syrrhophis interorbitalis_: Campbell and Simmons, 1962:194,
        fig. 1.

    [Illustration: FIG. 18: Left to right. _Syrrhophus interorbitalis_
       (UIMNH 38095, ×1.5), _S. nivocolimae_ (LACM 3203, ×1.3), and
       _S. teretistes_ (KU 75263, ×1.5).]

_Diagnosis._--Medium sized frogs, only known male 25.6 mm. snout-vent,
females 20.0-26.7 mm. snout-vent length (small sample); vocal slits in
males; finger tips expanded; first finger shorter than second; outer
metatarsal tubercle one-third size of inner; skin of dorsum shagreened,
that of venter smooth; diameter of tympanum 37.7-42.4 per cent that of
eye in both sexes; pale yellow-brown ground color mottled with brown;
limb bands broad, much wider than narrow light interspaces; interorbital
bar very long, edged with dark brown to black (Fig. 18).

_Remarks._--Duellman's (1958) measurements and proportions of
_S. interorbitalis_ were based exclusively on the type series, which is
composed of only females; therefore his _interorbitalis_ data are not
comparable with the data for the other species in his table. Campbell
and Simmons (1962) collected the only known male. The type series was
collected beneath rocks in a stream bed; the collectors heard calling
frogs in the bushes but were unable to obtain specimens (Langebartel and
Shannon, 1956). Campbell and Simmons (1962) reported that their specimen
had a poorly developed interorbital bar in life; in preservative the bar
compares favorably with the bar in the female (Fig. 18).

_Etymology._--Latin, in reference to the pale interocular band.

_Distribution._--Pacific lowlands of Sinaloa, México (Fig. 20).

_Specimens examined._--(10). MÉXICO, _Sinaloa_: 36 mi. N Mazatlán, UIMNH
38094-96, 67061 (holotype), 71970-74; 65 mi. N Mazatlán, LACM 13773.


=Syrrhophus modestus= Taylor

     _Syrrhophus modestus_ Taylor, 1942:304-06, pl. 29 [Holotype.--FMNH
        100048 (formerly EHT-HMS 3756), from Hacienda Paso del Río,
        Colima, México; collected on July 8, 1935, by Hobart M. Smith].
        Smith and Taylor, 1948:49-50.

     _Syrrhophus modestus modestus_: Duellman, 1958:2-5, 7, 14, pl. 1,
        fig. 1. Gorham, 1966:166.

_Diagnosis._--Small frogs, males 15.8-20.1 mm. snout-vent length, single
female 18.5 mm.; vocal slits present in males; finger tips widely
expanded; first finger shorter than second; inner metatarsal tubercle
about three times size of outer; skin of dorsum shagreened, that of
venter smooth; tympanum concealed; pale cream in preservative with dark
brown spots; limbs banded; bands on forearm and thigh poorly developed
or absent; interorbital bar absent.

_Remarks._--The tympanum is concealed in _S. modestus_,
_S. nivocolimae_, _S. pallidus_, _S. teretistes_, and to a lesser degree
in _S. interorbitalis_. However, if the specimen is permitted to dry
slightly, the annulus tympanicus becomes visible through the skin and a
tympanum/eye ratio can be computed.

One of the few cases of sympatry within the genus _Syrrhophus_ involves
this species; _modestus_ and _nivocolimae_ are known to be sympatric at
one locality in southwestern Jalisco, México.

Duellman (1958) used the trinomial for this population and named a new
subspecies, _pallidus_, from Nayarit. I consider _pallidus_ to be
specifically distinct from _modestus_ because there is no evidence of
genetic exchange, and there is no overlap in the distinguishing
morphological features. I do consider the two populations to be closely
related but feel the interrelationships between _modestus_, _pallidus_,
_nivocolimae_, and _teretistes_ are more complex than would be indicated
by the use of trinomials. The sympatric occurrence of _modestus_ and
_nivocolimae_ is significant; morphologically, they might otherwise be
regarded as subspecies. Although allopatric, similar arguments could be
advanced for the morphologically similar _pallidus_ and _teretistes_.
The four are here afforded species rank since morphological similarity
and allopatry are not sufficient grounds for the assumption of genetic
exchange.

    [Illustration: FIG. 19: _Syrrhophus modestus_ [left, UMMZ 115447
       (WED 11155)] and _S. pallidus_ (right, UMMZ 115453). ×2.2.]

_Etymology._--Latin, meaning unassuming, modest, in reference to the
small size of the species.

_Distribution._--Low elevations (up to 700 meters) in the lowlands and
foothills of Colima and southwestern Jalisco, México (Fig. 20).

_Specimens examined._--(14). MÉXICO, _Colima_: Hda. Paso del Río, FMNH
100048 (holotype), 100167, 100299, UIMNH 13300, UMMZ 110877 (2), USNM
139729; 7.2 km. SW Tecolapa, UMMZ 115477 (4); _Jalisco_: 17.6 km. SW
Autlan, 606 m., KU 102627; 3.2 km. N La Resolana, UMMZ 102100; Bahía
Tenacatita, UMMZ 84264.


=Syrrhophus nivocolimae= Dixon and Webb

     _Syrrhophus nivocolimae_ Dixon and Webb, 1966:1-4, Fig. 1
        [Holotype.--LACM 3200, from Nevado de Colima (6 airline miles west
        of Atenquique), Jalisco, México, 7800 feet; collected on July 20,
        1964, by Robert G. Webb].

_Diagnosis._--Small frogs, males 18.5-21.1 mm. snout-vent length, only
known female 24.1 mm. snout-vent; vocal slits present in males; finger
tips widely expanded; first finger shorter than second; inner metatarsal
tubercle about three times size of outer; skin of dorsum warty, that of
venter smooth; tympanum concealed, its diameter 30.0-39.3 per cent that
of eye in males; mid-dorsal brown band from interorbital bar to anus;
bands on limbs narrow, dark bands less than one-half width of light
bands, upper arm not banded; narrow interorbital light bar.

_Remarks._--This species is closely related to _S. modestus_ and differs
in color pattern and degree of wartiness of the skin. Dixon and Webb
(1966) held that _nivocolimae_ had no close relatives, but the condition
of the tympanum, size, nature of the outer palmar tubercle, relative
sizes of the metatarsal tubercles, and shape and size of the digital
pads all point to a close relationship between _S. modestus_,
_S. nivocolimae_, and _S. pallidus_.

    [Illustration: FIG. 20: Distribution of the species of the
       _modestus_ group: _interorbitalis_ (open circles), _teretistes_
       (solid circles), _modestus_ (open triangles), _pallidus_ (solid
       triangles) and _nivocolimae_ (square). Arrow indicates locality of
       sympatry between _modestus_ and _nivocolimae_. Solid line about the
       localities for _interorbitalis_ is a range estimate based on call
       records and specimens examined.]

Dixon and Webb (1966) reported that _S. nivocolimae_ has a large
tympanum (50.0-59.0 per cent diameter of eye). However, my examination
of the type series and several other specimens from Jalisco reveals that
the largest tympanum/eye ratio is 39.3 per cent. Therefore, the
tympanum/eye ratio in _S. nivocolimae_ is in agreement with those for
_S. modestus_, _S. pallidus_, and _S. teretistes_ (Table 6).

_Etymology._--_niv_, Latin, and Colima (Nevado de), meaning high on the
volcano, in reference to the higher distribution of this species (around
2000 meters) than other members of the group.

_Distribution._--Known from southwestern Jalisco, México, at moderate to
high elevations (600-2400 meters).

_Specimens examined._--(48) MÉXICO, _Jalisco_: 17.6 km. SW Autlán, 606
m., KU 102626, 102631; 6.4 km. W Atenquique, 2060 m., KU 102628-30,
102632; 8 km. W Atenquique, 1970 m., LACM 3210-12; 9.6 km. W Atenquique,
2360 m., LACM 3200 (holotype), 3201-09; 14.5 km. W Atenquique, 2000 m.,
LACM 25424-36, 25439-41, 25446; 15 km. W Atenquique, LACM 37044-46,
37244-47; 16 km. W Atenquique, 2105 m., LACM 25443-45; 17 km. W
Atenquique, 2180 m., LACM 25442.


=Syrrhophus pallidus= Duellman, New combination

     _Syrrhophus modestus_: Davis and Dixon, 1957:146.

     _Syrrhophus modestus pallidus_ Duellman, 1958:2-3, 5-7, 14, pl. 3
        [Holotype.--UMMZ 115452, from San Blas, Nayarit, México, sea
        level; collected on August 13, 1956, by William E. and Ann S.
        Duellman]. Zweifel, 1960:86-88, 91, 93-94, 118, 120-22. Gorham,
        1966:166.

     _Syrrhophis modestus pallidus_: Campbell and Simmons, 1962:194.

_Diagnosis._--Small frogs, males 17.9-19.3 mm. snout-vent length; vocal
slits in males; finger tips widely expanded; first finger shorter than
second; inner metatarsal tubercle about three times size of outer; skin
of dorsum shagreened, that of venter smooth; tympanum concealed, its
diameter 27.0-35.6 per cent of eye in males; ground color cream
vermiculated with brown, upper arm and thigh lacking, or with few,
indistinct, bands; interorbital bar absent.

_Remarks._--Considerable debate has been waged relative to the value of
subspecies and to the reasons for recognizing distinct disjunct
populations as species versus subspecies. Lacking evidence of genetic
exchange, I prefer to retain disjunct populations that are distinctive
as species.

All known specimens of _pallidus_ can be separated from those of
_modestus_ by color pattern. The two nominal species exhibit overlap in
proportions but the same can be said about nearly every species of
_Syrrhophus_; therefore, overlap in proportions can be disregarded in
assessing specific versus subspecific rank. Until contrary evidence is
forthcoming, I consider the disjunct populations heretofore held to be
subspecies of _modestus_ to be specifically distinct. The specimens of
the disjunct population of _pallidus_ on the Tres Marias do not differ
from the mainland population in Nayarit. This evidence, though perhaps
secondary, supports my contention that two species should be recognized.

_Etymology._--Latin, in reference to the pale ground color in comparison
with that of _S. modestus_.

_Distribution._--Low elevations in coastal Nayarit and on Islas Tres
Marias (Fig. 20).

_Specimens examined._--(12) MÉXICO, _Nayarit_: 18.8 mi. NW Ahuacatlán,
UIMNH 7808; San Blas, UMMZ 115452 (holotype), 115453-57; 17 km. NE San
Blas, 150 m., MSU 5085; 12.8 km. E San Blas, UIMNH 71979; 31 km. E San
Blas, UIMNH 71978; 13.5 km. N Tepic, UIMNH 71980-81.


=Syrrhophus teretistes= Duellman

     _Syrrhophus teretistes_ Duellman, 1958:2-3, 10-14, pl. 2, fig. 2
        [Holotype.--UMMZ 115451, from 4.8 km. NW Tepic, Nayarit, México,
        840 m.; collected on August 12, 1956, by William E. Duellman].
        Gorham, 1966:167.

_Diagnosis._--Medium-sized frogs, males 19.2-23.2 mm. snout-vent length,
single known female 24.8 mm. snout-vent; vocal slits in males; finger
tips widely expanded; first finger shorter than second; inner metatarsal
tubercle about three times size of outer; skin of dorsum shagreened,
that of venter smooth; tympanum partially concealed, its diameter
28.6-43.8 per cent of eye in males; ground color brown vermiculated with
dark brown to nearly black; upper arm and thigh banded; interorbital
light bar absent.

_Remarks._--_S. teretistes_ appears to be most closely related to
_S. pallidus_; I consider it to be an upland derivative of _pallidus_.
Morphologically, the differences between the two are few, but lacking
evidence of genetic exchange they are retained as species.

_Etymology._--Greek, in reference to the whistle-like nature of the
call.

_Distribution._--Moderate elevations (840-1200 meters) in the Sierra
Occidental of Nayarit, Sinaloa, and Durango, México (Fig. 20).

_Specimens examined._--(13) MÉXICO, _Nayarit_: 4.8 km. NW Tepic, 840 m.,
UMMZ 115451 (holotype). _Sinaloa_: Santa Lucía, 1090 m., KU 75263-72; 1
km. NE Santa Lucía, 1156 m., KU 78257; 2.2 km. NE Santa Lucía, 1156 m.,
KU 78258.




DISCUSSION


There are relatively few clear-cut morphological differences among the
fourteen species now assigned to _Syrrhophus_. The majority of the
species are allopatric and differ primarily in color patterns. Sympatric
occurrence serves as an indicator of specific distinctness and is one of
the more practical tests of species validity when cross-breeding
experiments are not possible. Two cases of sympatric occurrence are
known for the species of _Syrrhophus_ in western México: _modestus_ and
_nivocolimae_ are sympatric in southern Jalisco and _pipilans nebulosus_
and _rubrimaculatus_ are sympatric in southeastern Chiapas. In eastern
México, _longipes_ and _verrucipes_ are sympatric in southern Hidalgo,
and _longipes_ is sympatric with _cystignathoides_, _dennisi_, and
_guttilatus_ in southern Tamaulipas. _Syrrhophus cystignathoides_ and
_leprus_ are apparently sympatric in central Veracruz.

Subspecific assignments have been made only when there is evidence of
intergradation. The sympatric occurrence of morphologically similar
species in this genus has led me to adopt a conservative approach to the
degree of difference philosophy. I have therefore recognized all
morphologically distinct allopatric populations as species.

    [Illustration: FIG. 21: Generic distributions of _Syrrhophus_
       (stipple) and _Tomodactylus_ (hatching). Black areas are zones
       of intergeneric sympatry.]

_Syrrhophus_ is closely allied to another Mexican leptodactylid genus,
_Tomodactylus_, which was revised by Dixon (1957), who along with
numerous other authors noted the close relationship between the two
genera. There is an almost complete lack of sympatry between the two
genera; in very few places in México do they coexist (Fig. 21).
_Tomodactylus_ has its greatest diversity in the Cordillera Volcánica
and Sierra Madre del Sur, whereas _Syrrhophus_ reaches its greatest
diversity in the Sierra Madre Oriental and eastern foothills. The
species of both genera are about the same size and presumably have
similar requirements insofar as food, breeding sites, and habitat
selection.

Four cases of intergeneric sympatry are known for the two genera:
1) the Chilpancingo region of Guerrero, 2) the lowlands of Colima and
the mountains just inland in Jalisco, 3) the lowlands of central Nayarit,
and 4) the Sierra Madre Occidental on the Durango-Sinaloan border. The
apparent sympatry in the Chilpancingo region involves four species:
_S. pipilans_, _T. albolabris_, _T. dilatus_, and _T. nitidus_. Of the
four, _T. dilatus_ appears to be completely allopatric in that it occurs
at higher altitudes (above 2000 meters), whereas the other three occur
below 1800 meters in the region (Davis and Dixon, 1965). In the
Colima-Jalisco region, _Tomodactylus_ tends to occur higher (Dixon and
Webb, 1966) than some of the _Syrrhophus_, but one subspecies of
_Tomodactylus nitidus_ is a lowland frog, occurring sympatrically with
the lowland _Syrrhophus modestus_. A similar situation is observed in
Nayarit; the lowland _Tomodactylus_ occurs sympatrically with the small
_Syrrhophus pallidus_. In both cases the _Syrrhophus_ is smaller than
the _Tomodactylus_.

    [Illustration: FIG. 22: Altitudinal distributions of _Syrrhophus_
       and _Tomodactylus_. Widths of the columns are proportional to the
       numbers of species at a given altitude; narrowest width equals one
       species.]

Frogs of the genus _Syrrhophus_ tend to occur at lower elevations than
do their close relatives of the genus _Tomodactylus_ (Fig. 22). This
generalization is complicated by the occurrence in the Sierra Madre
Oriental in relatively high altitude _Syrrhophus_ (up to 2000 m.) and
the occurrence in Michoacán of low altitude _Tomodactylus_ (to sea
level). There are no _Tomodactylus_ in the Sierra Madre Oriental,
whereas the genus _Syrrhophus_ is represented in the lowlands of western
México (_modestus_ group). _Syrrhophus_ and _Tomodactylus_ exhibit
essentially parapatric distributions. The two genera as now composed can
be characterized as low to moderate elevation frogs (_Syrrhophus_) and
moderate to intermediate elevation frogs (_Tomodactylus_).




LITERATURE CITED


BAIRD, S. F.

     1859.  Reptiles of the Boundary. United States and Mexican Boundary
            Survey, pp. 1-35, pls. 1-41.


BARBOUR, T.

     1923.  The reappearance of Batrachyla longipes. Proc. New England
            Zool. Club, 8:81-83.


BARBOUR, T., and A. LOVERIDGE

     1946.  Typical reptiles and amphibians; supplement. Bull. Mus. Comp.
            Zool., 96:59-214.


BOULENGER, G. A.

     1882.  Catalogue of the Batrachia Salientia ... British Museum.,
            2nd ed.

     1888.  Note on the classification of the Ranidae. Proc. Zool. Soc.
            London, 1888, pt. 2:204-06.


CAMPBELL, H. W., and R. S. SIMMONS

     1962.  Notes on some reptiles and amphibians from western Mexico.
            Bull. So. California Acad. Sci., 61:193-203.


CONANT, R.

     1958.  A field guide to reptiles and amphibians. Houghton-Mifflin
            Co. Boston. 366 pp.


COPE, E. D.

     1866.  On the structures and distribution of the genera of the
            arciferous Anura. J. Acad. Nat. Sci. Philadelphia, n. ser.,
            6:67-112.

     1877.  Tenth contribution to the herpetology of tropical America.
            Proc. Amer. Philos. Soc., 17:85-98.

     1878.  New genus of Cystignathidae from Texas. Amer. Nat.,
            12:252-53.

     1879.  Eleventh contribution to the herpetology of tropical America.
            Proc. Amer. Philos. Soc., 18:261-77.

     1885.  A contribution to the herpetology of Mexico. _Ibid._,
            22:379-404.


DAVIS, W. B., and J. R. DIXON

     1957.  Notes on Mexican amphibians, with description of a new
            _Microbatrachylus_. Herpetologica, 13:145-47.

     1965.  Amphibians of the Chilpancingo Region, Mexico. _Ibid._,
            20:225-33.


DÍAZ DE LEÓN, J.

     1904.  Indice de los Batracios que se enquentran en la Republica
            Méxicana. Imprenta de Ricardo Rodriquez Romo. Aguascalientes.
            40 pp.


DIXON, J. R.

     1957.  Geographic variation and distribution of the genus
            Tomodactylus in Mexico. Texas J. Sci., 9:379-409.


DIXON, J. R., and R. G. WEBB

     1966.  A new _Syrrhophus_ from Mexico (Amphibia: Leptodactylidae).
            Cont. Sc., Los Angeles Co. Mus., 102:1-5.


DUELLMAN, W. E.

     1958.  A review of the frogs of the genus _Syrrhophus_ in western
            Mexico. Occ. Pap. Mus. Zool. Univ. Michigan, 594:1-15.

     1960.  A distributional study of the amphibians of the Isthmus of
            Tehuantepec, Mexico. Univ. Kansas Publs. Mus. Nat. Hist.,
            13:19-72.


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.


FOUQUETTE, M. J.

     1960.  Call structure in frogs of the family Leptodactylidae. Texas
            J. Sci., 12:201-15.


GADOW, H.

     1905.  The distribution of Mexican amphibians and reptiles. Proc.
            Zool. Soc. London, 1905, pt. 2:191-244.


GORHAM, S. W.

     1966.  Liste der rezenten Amphibien und Reptilien.... Das Tierreich.
            Lief, 85:1-222.


GÜNTHER, A. C. L. G.

     1885-1902. Biologia Centrali-Americana. Reptilia and Batrachia.
            326 pp., 76 pls. Syrrhophus section dated 1900.


KELLOGG, R.

     1932.  Mexican tailless amphibians in the United States National
            Museum. Bull. U.S. Natl. Mus., 160.


LANGEBARTEL, D. A., and F. A. SHANNON

     1956.  A new frog (Syrrhophus) from the Sinoloan lowlands of Mexico.
            Herpetologica, 12:161-65.


LYNCH, J. D.

     1963.  The status of _Eleutherodactylus longipes_ (Baird) of Mexico
            (Amphibia: Leptodactylidae). Copeia, (3):580-81.

     1964.  Additional hylid and leptodactylid remains from the
            Pleistocene of Texas and Florida Herpetologica. 20:141-42.

     1967.  _Epirhexis_ Cope, 1866 (Amphibia: Salientia): request for
            suppression under the plenary powers. I. N. (S). Bull. Zool.
            Nomencl., 24:313-15.

     1968.  Genera of leptodactylid frogs in México. Univ. Kansas Publs.,
            Mus. Nat. Hist., 17:503-15.


MARTIN, P. S.

     1958.  A biogeography of reptiles and amphibians in the Gomez Farias
            region, Tamaulipas, Mexico. Misc. Publs. Mus. Zool. Univ.
            Michigan, 101:1-102.


MILSTEAD, W. M., J. S. MECHAM, and H. MCCLINTOCK

     1950.  The amphibians and reptiles of the Stockton Plateau in
            northern Terrell County, Texas. Texas J. Sci., 2:543-62.


NEILL, W. T.

     1965.  New and noteworthy amphibians and reptiles from British
            Honduras. Bull. Florida State Mus., 9:77-130.


NIEDEN, F.

     1923.  Anura I ... Das Tierreich. Lief., 46:1-584.


PETERS, W.

     1871.  Über neue Amphibien ... des Konigl. Zoologischen Museums.
            Monatsb. k. k. Preuss. Akad. Wiss. Berlin, 1870:641-52.


SCHMIDT, K. P., and T. F. SMITH

     1944.  Amphibians and reptiles of the Big Bend Region of Texas.
            Field Mus. Nat. Hist., zool. ser., 29:75-96.


SMITH, H. M.

     1947.  Notes on Mexican amphibians and reptiles. J. Washington Acad.
            Sci., 37:408-12.


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

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


STEJNEGER, L.

     1915.  A new species of tailless batrachian from North America.
            Proc. Biol. Soc. Washington, 28:131-32.


TAYLOR, E. H.

     1940a. A new eleutherodactylid frog from Mexico. Proc. New England
            Zool. Club, 18:13-16.

     1940b. Two new anuran amphibians from Mexico. Proc. U.S. Natl.
            Mus., 89:43-47, 1 pl.

     1940c. A new Syrrhophus from Guerrero, Mexico. Proc. Biol. Soc.
            Washington, 53:95-98, 1 pl.

     1940d. New species of Mexican Anura. Univ. Kansas Sci. Bull.,
            26:385-405.

     1940e. Herpetological miscellany no. I. _Ibid._, 26:489-571.

     1942.  New Caudata and Salientia from México. _Ibid._, 28:295-323.

     1943.  Herpetological novelties from Mexico. _Ibid._, 29:343-61.

     1952.  A review of the frogs and toads of Costa Rica. _Ibid._,
            35:577-942.


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

     1945.  Summary of the collections of amphibians made in Mexico under
            the Walter Rathbone Bacon Traveling Scholarship. Proc. U.S.
            Natl. Mus., 95:521-613.


TIHEN, J. A.

     1960.  Notes on Late Cenozoic hylid and leptodactylid frogs from
            Kansas, Oklahoma and Texas. Southwest. Nat., 5:66-70.


WRIGHT, A. H., and A. A. WRIGHT

     1949.  Handbook of frogs and toads. 3rd ed. Comstock. 640 pp.


YARROW, H. C.

     1882.  Checklist of North American Reptilia and Batrachia, with
            catalogue of specimens in U.S. National Museum. Bull. U.S.
            Natl. Mus., 24:1-249.


ZWEIFEL, R. G.

     1960.  Results of the Puritan-American Museum of Natural History
            Expedition to Western Mexico. 9. Herpetology of the Tres
            Marias Islands. Bull. Amer. Mus. Nat. Hist., 119:81-128.




TRANSCRIBER'S NOTES


Although _Syrrhophus marnocki_ and _Syrrhophus marnockii_ both appear
in this text, a literature search shows that both spellings have been
used and the two instances where there is only one "i" at the end are
in reference to priviously published names. Therefore, they were left
as is. With the exception of the list below and a number of silent
corrections, the text presented is that of the original printed version.

Typographical Corrections

 Page  Correction
 ====  ======================
   3   otherwse => otherwise
   5   poltypic => polytypic
  12   interorbtal => interorbital
  14   neublosus => nebulosus
  16   Cuidad => Ciudad
  16   1946-170 => 1946:170
  22   rubrimacultaus => rubrimaculatus
  27   resemblence => resemblance

Text Emphasis

 _Text_ - Italics

 =Text= - Bold