the production of vast
quantities of sperm are an adaptation for successful breeding in
torrential streams (Duellman, 1965:164).

All individuals were found in trees and bushes near streams in cloud
forest at night in February. The type locality is the same as that of
_Hyla pentheter_ and _Hyla thorectes_, discovered by Kraig Adler in
June, 1964. Our field work there in February, 1966, resulted in finding
_Hyla altipotens_, _H. pellita_, and _Ptychohyla leonhardschultzei_, but
no individuals of the species found by Adler. A visit to the same
locality in August, 1966, revealed no individuals of either _H.
altipotens_ or _pellita_; instead _pentheter_ and _thorectes_ were found
along the stream.

Duellman (1965:166) listed a specimen (TCWC 16184) of _Hyla chaneque_
from Los Fustes, 3 kilometers east of San Sebastian, Oaxaca.
Reexamination of this specimen reveals that it is _Hyla altipotens_.
The frog was obtained by Dilford Carter on April 29, 1960; it was under
a rock at the edge of a stream in an oak-pine-cypress association at an
elevation of 1800 meters.

The specific name _altipotens_ is Latin, meaning mighty, here used in
allusion to the supposed potentiality of fertilization by the production
of vast quantities of sperm in the large testes.

Plectrohyla hartwegi new species

Plate 19

_Holotype._--Adult male, UMMZ 94428, from Barrejonel (19 kilometers west
of Chicomuselo), Chiapas, Mexico, elevation 1000 meters, obtained on
June 12, 1941, by Eizi Matuda.

_Paratypes._--Two subadult males, KU 58873 from Paraje El Triunfo, north
of Mapastepec, Chiapas, Mexico, elevation 2050 meters, obtained on May
12, 1960, by Miguel Alvarez del Toro, and UIMNH 40837 from Cerro Azul
Oaxaca, Mexico, obtained on March 7, 1956, by Thomas MacDougall.

_Diagnosis._--A _Plectrohyla_ having a bifid prepollex, bold mottling on
flanks and ventral surfaces of shanks, and vertical dark bars on
anterior and posterior surfaces of thighs, and lacking vocal slits and
outer tarsal fold.

_Description of holotype._--Adult male having a snout-vent length of
63.8 mm.; tibia length 34.9 mm., 54.7 per cent of snout-vent length;
foot length (measured from proximal edge of inner metatarsal tubercle to
tip of longest toe) 31.1 mm., 48.7 per cent of snout-vent length; head
length 19.7 mm., 30.9 per cent of snout-vent length; head width 22.6
mm., 35.4 per cent of snout-vent length. Snout short, distance from
level of anterior edge of orbit to