Part 2

The terminal phalanges of Syrrhophus, Tomodactylus, and all Eleutherodactylus (except the frogs of the augusti group) are distinctly T-shaped. In the latter, the bones are knob-shaped distally (Fig. 4). T-shaped terminal phalanges also are present in Lithodytes and Trachyphrynus but not in other leptodactylid genera. At least one species of Eupsophus (E. quixensis) has terminal phalanges that resemble those of the Eleutherodactylus augusti group. Several species of Eleutherodactylus, Syrrhophus, and Tomodactylus with slender fingers have T-shaped terminal phalanges although the terminal dilations proportionately are only scarcely wider than the finger tips in the Eleutherodactylus augusti group. The presence of a terminal groove at the tip of the finger is an external indicator of the T-shaped terminal phalanges.

Skull

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

Pectoral Girdle

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

GENERIC ACCOUNTS

Genus ~Eleutherodactylus~ Dumeril and Bibron, 1841

Type-species.--Hylodes martinicensis Tschudi, 1838

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

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

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

Etymology.--Greek (eleuthero + dactylus) meaning free-toed.

Genus ~Engystomops~ Jiménez de la Espada, 1872

Type species.--Engystomops petersi Jiménez de la Espada, 1872

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

Composition.--Four nominal species (E. petersi, E. pustulatus, E. pustulosus and E. schereri).

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

Etymology.--Greek (engys + stoma) meaning narrow-mouthed.

Genus ~Hylactophryne~ new genus

Type-species.--Hylodes augusti Dugés, 1879

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

Composition.--Two species, H. augusti and H. tarahumarensis, the former composed of four subspecies (Zweifel, 1956).

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

Etymology.--Greek (hylactor + phryne) meaning barking toad; in reference to the voice and common name.

Genus ~Leptodactylus~ Fitzinger, 1826

Type-species.--Leptodactylus typhonia Fitzinger, 1826

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

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