Color (in preservative): pale tan above with dark brown mark in occipital region and large irregular brown mark extending from scapular region to sacral region; anterior and posterior surfaces of thighs and flanks lacking pigment; dorsal surfaces of arms, shanks, and feet tan with brown transverse bars (two on each forearm, two on left shank, one on right shank, and one on each foot); entire dorsal surfaces, except hands and first four toes, peppered with black; venter creamy white; roof of mouth between, and anterior to, choanae speckled with minute black flecks.
Color (in life): yellowish tan above with reddish brown flecks (later changed to pale brown with dull olive-green interorbital bar, blotch on back, and flecks on dorsum); hands, feet, and anterior and posterior surfaces of thighs dull yellow; belly white; creamy white stripes on outer edge of forearm, foot, and above anus; iris pale silver-bronze.
Variation.—Three adult males (including holotype) have snout-vent lengths of 25.2-27.3 (mean 26.5) mm., and two females have 28.6 and 31.6 (mean 30.1) mm. One juvenile has a snout-vent length of 21.5 mm. No significant variation occurs in the proportions. Males have 6-8, and females have 8 and 9, prevomerine teeth. The tympanum is completely concealed in all specimens.
All specimens have distinct transverse bars on the limbs; the number of bars on the shank varies from one to four. Two individuals are dark brown dorsally; in these the small black flecks either are not visible or are absent; flecks are present on the dorsal surfaces of four specimens that are tan or pale brown above with darker brown irregular markings.
The coloration in life consisted of olive-green or olive-brown markings on the body and olive-green or brown bars on the limbs. The dorsal ground color was yellowish tan or pale brown in all individuals.
Comparisons.—Hyla pellita differs from all known Middle American Hyla, except mixe, mixomaculata, nubicola, and pinorum, by having a concealed tympanum. The first three of these differ from pellita in greater size and by having many bands on the hind limbs. Superficially H. pellita resembles Hyla pinorum, which likewise has a tan dorsum with irregular markings and limbs with transverse bars. Hyla pinorum differs from pellita by having a proportionately larger head, no transverse bands on the thighs, and large tubercles below the anus. Furthermore, in pinorum the quadratojugal articulates with the maxillary, whereas in pellita the quadratojugal is reduced to a small spur and does not articulate with the maxillary.
Remarks.—All individuals were found on low vegetation along streams in cloud forest at night. No specimens were found when the type locality was revisited in August, 1966.
Duellman (1960) placed Hyla pinorum Taylor in the synonymy of Ptychohyla leonhardschultzei Ahl. At that time only the holotype, a female, of H. pinorum was known. In 1964 Kraig Adler and I independently collected frogs and associated tadpoles in Guerrero that subsequently proved to be Hyla pinorum and provided evidence that Hyla pinorum is not conspecific with Ptychohyla leonhardschultzei.
The specific name pellita is Latin, meaning covered with skin, and is here used in reference to the complete concealment of the tympanum beneath the skin.
Hyla siopela new species