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

Plate 18

_Holotype._--Adult male, KU 100981, from a small stream on the west
slope of Cofre de Perote, Veracruz, Mexico, elevation 2500-2550 meters;
obtained on July 30, 1966, by William E. Duellman.

_Paratypes._--KU 100976-80, 100982-5, same locality, date, and
collector; KU 105628-9, same locality, obtained on June 18, 1966, by
Howard L. Freeman; UIMNH 57687-57701, same locality, obtained on July
30-31, 1964, by Macreay J. Landy and John D. Lynch.

_Diagnosis._--A member of the _Hyla bistincta_ group characterized by
truncate snout with short rostral keel; fingers having little webbing
and bearing large discs; axillary membrane absent; thoracic fold weak;
prepollex large, flat, bearing small nuptial spines; vocal slits absent;
dorsum green or tan with small irregular dark spots; flanks mottl