_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, Mexico, 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. Genus ~Syrrhophus~ Cope, 1878 _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 transverse groove at tip of each digit; lumbo-inguinal and inguinal gland flattened, irregular in outline, not compact and oval; axillary glands present or not; plantar supernumerary tubercles numerous, more than eight, usually extending between metatarsal tubercles; tarsus lacking tubercles or folds; toes free or basally webbed; terminal phalanges T-shaped; sternum cartilaginous, lacking 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, usually lacking dentigerous processes and teeth; maxillary and premaxillary bones dentate; occipital condyles separated; development direct. _Composition._--Thirteen species; the species described as, or later referred to, _Syrrhophus_ from Lower Central America and South America are _Eleutherodactylus_ or _Eupsophus_.