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,
Mexico, to Trinidad, Bolivia, and Peru, east of the Andes.

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

Genus ~Hylactophryne~ new genus

_Type-species._--_Hylodes augusti_ Duges, 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, Mexico, and a relict population on
Cerro Quingola (just west of the Isthmus of Tehuantepec,
Mexico).

_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 generall