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.

Type-species.—Leptodactylus typhonia Fitzinger, 1826

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

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

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

Entymology.—Greek (leptos + dactylus) meaning slender toes.

Type-species.—Syrrhophus marnockii Cope, 1878

Diagnosis and definition.—Small to medium sized frogs (18 to 40 mm. snout-vent) having slight to prominent digital expansions with