Anal opening directed posteroventrally at mid-level of thighs; anal sheath long, tubular. Skin smooth on dorsum and on ventral surfaces of shanks, granular on throat, belly, and ventral surfaces of arms and thighs. Tongue ovoid, widest posteriorly, neither notched nor free behind. Prevomerine teeth 6-7, situated on robust transverse ridges between small, ovoid choanae. Vocal slits absent. Testes large, ovoid, granular; length of left testis 11.0 mm. Color (in preservative): brown above with many darker brown spots and narrow middorsal stripe on back; six or seven dark brown transverse bars on each segment of hind limbs and four bars on each forearm; flanks white with dark brown spots; anterior surfaces of thighs creamy white with brown reticulations; posterior surfaces of thighs dark brown with creamy yellow flecks; stripe on snout, canthus, edge of upper eyelid, and supratympanic fold tan; ventral surfaces of feet brown; rest of venter creamy white; stripe above anus white. Color (in life): green above with slightly darker green spots; dorsal surfaces of upper arms and thighs tan with green transverse bars; upper surfaces of forearms and shanks green with darker green transverse bars; feet, fourth and fifth toes, and third and fourth fingers tan with brown transverse bars; other fingers and toes tan with brown flecks. Ventral surfaces creamy yellow, brightest on throat and chest; flanks and anterior surfaces of thighs bright creamy yellow with dark brown reticulations and spots; posterior surfaces of thighs and ventral surfaces of feet dark brown with yellow flecks; ventral surfaces of hands and webbing on hands and feet yellowish tan. Labial stripe tan; stripes on outer edge of forearm, along outer edge of foot, and above anus cream-color; stripe on canthus, edge of upper eyelid, and on supratympanic fold bronze-color. Iris pale bronze with black reticulations and faint median, horizontal copper-colored streak; pupil horizontally elliptical with ventral notch; palpebral membrane clear above, pale bluish green with brown reticulations below. _Variation._--In life all individuals had creamy yellow venters and yellow flanks and anterior surfaces of thighs with brown or black spots and mottling. Most of the adults were colored like the holotype, but one was a much darker olive-green, and one was uniform brown above with a dark brown middorsal stripe. Most subadults (snout-vent lengths 31.6-50.1 mm.) were pale reddish tan above with darker reddish brown bars on the limbs and blotches on the back. The side of the head was dark brown and the stripe along the canthus, edge of upper eyelid, and supratympanic fold was yellowish tan. Some individuals had a dark brown middorsal stripe. The posterior surfaces of the thighs were dull yellowish tan; yellow flecks were present in the larger individuals. TABLE 2.--Variation in Measurements and Proportions in Hyla altipotens. (Means Are Given in Parentheses Below the Observed Range.)