Mouth large; thin fleshy lips greatly expanded and forming large funnel-shaped disc; width of mouth two-thirds greatest width of body; outer edge of lips having one row of small papillae; inner surfaces of mouth smooth; scattered large papillae forming one nearly complete row around teeth; other large papillae laterally; beaks moderately developed, bearing long, pointed denticulations; no lateral projections on upper beak; tooth-rows 3/3, all short; second and third upper rows subequal in length; first upper row shorter; first and third upper rows interrupted medially; first lower row interrupted medially, equal in length to second and third upper rows; second lower row slightly shorter; third lower row shortest. Body mottled brown and creamy gray above and below; mouth colored like body; caudal musculature creamy tan; caudal fin transparent; dark brown streak mid-laterally on anterior third of caudal musculature; rest of tail and all of caudal fin heavily flecked with brown; eye red in life. _Variation._--The third upper tooth-row is interrupted in all specimens; in some individuals the first upper and first lower rows are complete. The variation in size and proportions is given in Table 2. The dark brown lateral streak on the anterior part of the caudal musculature is distinct on most specimens; the only other variation in coloration is in the amount of brown flecking on the caudal musculature and fin. _Comparisons._--_Ptychohyla schmidtorum schmidtorum_ differs from _P. schmidtorum chamulae_ as stated in the diagnosis and in having pale creamy tan, as opposed to dark brown, webbing on the feet; and from _P. ignicolor_ in having a depressed, as opposed to a flat, internarial region. Tadpoles of _P. s. schmidtorum_ have a mottled appearance, as opposed to the more uniform brown color of _P. s. chamulae_. _Ptychohyla schmidtorum schmidtorum_ and several species of _Plectrohyla_ are sympatric. All species of the latter genus have a bony prepollex, rugose skin on the dorsum, and heavy body; also sympatric is _Ptychohyla e. euthysanota_, which has a tarsal fold and in breeding males spinous nuptial tuberosities. _Life History._--This species breeds in clear mountain streams where males call from vegetation along the stream. The call consists of series of short notes, three to nine notes per series, sounding like "raa-raa-raa." The duration of each note is approximately .065 of a second, and has a rate of 96 to 119 pulses per second; the dominant frequency is about 3400 cycles per second. The call is almost indistinguishable from that of _Ptychohyla schmidtorum chamulae_.