Río Aloapan Treefrog

Member of the Hyla pinorum group according to Duellman (1970) . Campbell and Brodie (1992) had previously assigned this species as being Hyla melanomma, now elevated to species level in Campbell and Duellman (2000) . This is a small treefrog with dark brown spots on limbs, body and head. Pale brown in groin areas with cream color and brown spots on the flanks. Snout acuminate when viewed dorsally and the diameter of the tympanum is less than 50% of the diameter of the eye. Head is as wide as body and slightly wider than it is long. Head width is 35.2% SVL, head length is 34.5% SVL. the loreal region (between anterior of eye and posterior of nostril) is slightly concave. Lips thin and not flared. Nostrils are protuberant and directed anterolaterally. Diameter of tympanum is 36.4% diameter of eye. Weak transverse fold on wrist, axillary membrane extending approximately 1/3 of upper arm. Cloacal opening is directed posteroventrally at upper level of thighs. Single, median, subgular vocal sac is present in males. Vocal slits extend from the midlateral base of the tongue to the angle of the jaws. In life, the dorsum is a dull bronze-brown with black flecks on body and dark brown to black irregular marks on limbs. Brownish black canthal (corner of eye), sypratympanic, and lateral stripes. Venter is cream colored and the iris is a pale copper with black flecks. Tadpoles of this species are unknown.

Only known from the vicinity of its type locality along the Rio Aloapan in the Sierra Mazateca of Oaxaca, Mexico, at an elevation of 405 m in lower montane rainforest (cloud forests).

The three males which have been collected were found while the general weather conditions consisted of being overcast, it had not rained in several days.