_Definition._--The species forming the group are small to moderate-sized tree frogs (maximum snout-vent length of males of various species 20-49 mm.), distinguished from other groups in the genus _Hyla_ as follows: Brown, grayish brown, or yellowish tan above; thighs plain, marbled with dark brown, or having vertical bands; vocal sac single, median, subgular; snout flat, protruding, rounded or pointed; webbing between fingers reduced or absent; web between first and second toes reduced to fringe on second toe, rest of toes about half webbed; tarsal fold reduced or absent; shanks robust; inner metatarsal tubercle larger than outer; prevomerine teeth on transverse ridges between small to large sized choanae; skull generally longer than wide; nasals large (length more than 40 per cent total length of skull) and having pointed maxillary processes; maxillary bearing small ventromedial palatine process; quadratojugal slender, always joined to maxillary by bony suture; auditory region of proötic slender and short; delicate spatulate columella ventral to crista parotica, broad basally, compressed anterolaterally, slightly rounded distally; anterior arm of squamosal extending about half distance to maxillary; sphenethmoid wider than long; frontoparietal fontanelle present or absent; prevomerine, premaxillary, and maxillary teeth present; prevomer with two lateral processes forming incomplete bony margin to internal nares; tadpoles having pointed xiphicercal tail, snout short, rounded; 2/3 tooth rows; dorsal fin deeper than ventral fin; sinistral spiracle; short dextral anal tube not reaching edge of ventral fin; mating calls consisting of single long note or series of short notes. _Composition._--This group contains about 24 currently recognized species, most of which occur in Brazil. Only five species--_boulengeri,_ _elaeochroa_, _foliamorta_, _rubra_, and _staufferi_ with two subspecies--occur in Central America. _Hyla boulengeri_ and _rubra_ are widespread in South America, and _foliamorta_ occurs in Colombia, whereas the other species are known only from Middle America. _Distribution._--The species of the _Hyla rubra_ group range from the lowlands of northern Argentina and Bolivia to southern Tamaulipas and Guerrero, México. _Comments._--In Central America two subgroups of species can be recognized. _Hyla boulengeri_ and _H. foliamorta_ are distinctive in the large size of adults (snout-vent lengths 41-49 mm.); both have prominent bars on the thighs, a well-defined interorbital triangular mark, blotches or spots dorsally, and large choanae. _Hyla elaeochroa,_ _H. rubra,_ and _H. staufferi_ are smaller (snout-vent lengths 29-40 mm.); they have the thighs weakly barred or vermiculate anteriorly and posteriorly or unmarked, an ill-defined interorbital triangular mark, linear markings dorsally, and small choanae. Key to Species and Subspecies