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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, Mexico, 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
Mexico, 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 Mexico and
concluded that there were five species (two polytypic). Dixon and Webb
(1966) described an additional species from Jalisco, Mexico. 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
Mexico. 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 Mexico and northern Central America, it
became necessary to reexamine 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 Mexico, Texas, and El
Peten of Guatemala, and seven species (one polytypic) in western Mexico.
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. Boehlke 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 x6.5.]
[Illustration: FIG. 2: Palmar views of hands of two species of the
western complex of _Syrrhophus_. _pipilans_ (left, KU 58908, x6)
and _teretistes_ (center, KU 75269, and right, KU 75263,
respectively, x9).]
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, x6),
(B) _leprus_ (UIMNH 42726, x6), (C) _verrucipes_ (UIMNH 15995, x6),
and (D) _longipes_ (TCWC 12179, x4.6).]
_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, Mexico 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 Cordoba, Veracruz, Mexico, 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 Potosi, Mexico. 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 Rio Grande
embayment to central Veracruz, Mexico (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
Mexico; 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 Potosi, 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 Rio Grande embayment in Texas to central Nuevo
Leon and Tamaulipas, Mexico. Intergrades are known from southern
Tamaulipas and adjacent San Luis Potosi, Mexico (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-Rio Grande State Park, UMMZ 114378; 6 mi. S McAllen, TNHC
7136-39; Santa Ana Refuge, TCWC 13495-96; Weslaco, TCWC 17658-60.
MEXICO, _Nuevo Leon_: 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_ x _S. c. campi_ (88)] MEXICO, _San
Luis Potosi_: 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 Acuna, 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 Gomez Farias, 450 m.,
UMMZ 101165; 8 km. NE Gomez Farias, Pano Ayuctle, UMMZ 102264, 102924
(6); 8 km. NW Gomez Farias, 1060 m., LSUMZ 11084, UMMZ 101199, 102928
(5), 102929-32, 110124 (3); Rio 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 x2, sides of heads x3.]
=Syrrhophus cystignathoides cystignathoides= (Cope), New combination
_Phyllobates cystignathoides_ Cope, 1877:89-90 [Syntypes.--USNM
32402-32409, from Potrero, near Cordoba, Veracruz, Mexico,
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_: Guenther, 1900:218.
_Syrraphus cystignathoides_: Diaz de Leon, 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 (Guenther 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, Mexico. 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 Potosi to Central Veracruz,
Mexico (Fig. 5).
_Specimens examined._--(130), MEXICO, _Puebla_: Necaxa, UMMZ 69519-20.
_San Luis Potosi_: 5 km. W Aguismon, LSUMZ 4962-63; along Rio 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 Cordoba, FMNH 104588, UIMNH 13321; Cuautlapam,
1000 m., FMNH 106477-80, KU 100364, UIMNH 58200-03, UMMZ 105392; Fortin
de las Flores, UIMNH 13322, 13339; 1.6 km. N Fortin de las Flores, UIMNH
42799-808, UMMZ 105389; 3.2 km. N Fortin de las Flores, UIMNH 26633-35;
4.8 km. N Fortin de las Flores, UIMNH 71967-68; 3.2 km. W Fortin 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 Rio, 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 Tezuitlan (Puebla), UMMZ 105388;
Teocelo, FMNH 70437-38, KU 26080, 26790; 3.2 km. N Teocelo, FMNH 70439,
70441-42; 9.6 km. NW Tihuatlan, 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, Mexico, 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_: Guenther, 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, x2; right, KU 26106,
x1.7). Side of head (UIMNH 42726, x7).]
[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, Mexico.
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, Mexico, 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_: Chinaja, KU
55961-62. _El Peten_: 15 km. NW Chinaja, KU 55963; Piedras Negras, USNM
114085-92; Tikal, UMMZ 117035; Uaxactun, AMNH 55121-22.
MEXICO, _Oaxaca_: Cerro San Pedro del Isthmo, UIMNH 35510; Finca La
Gloria, USNM 114093; 30.5 km. N Matias 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; Fortin 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
Andres 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); Volcan San Martin, south slope, UMMZ 118223; Volcan San
Martin, 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, Mexico, 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, x1.6; lower right, KU 58910, x4) and _S. verrucipes_
(upper left, UIMNH 15995, x1.6; lower left, UIMNH 15989, x3.7).]
_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, Mexico (Fig. 7); probably extending into
adjacent Guatemala.
_Specimens examined._--(48) MEXICO, _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 Jeronimo, 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, Mexico; collected in 1877 by
Alfredo Duges].
_Syrrhopus guttulatus_: Boulenger, 1888:204-06.
_Syrrhaphus guttulatus_: Guenther, 1900:317.
_Syrraphus guttulatus_: Diaz de Leon, 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 Leon, Mexico, 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 Potosi, San Luis Potosi, Mexico;
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, x1.4; lower left, UIMNH 55519, x2.3) and _S. marnockii_
(upper right, TCWC 9317, x1.4; lower right, TCWC 13510, x2.1).]
_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 Mexico. 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.