the flanks are either plain or marked with
small spots or flecks. Structurally, _P. hartwegi_ belongs in the
_guatemalensis_ group of the genus, containing _avia_, _glandulosa_,
_guatemalensis_, and _pycnochila_. The species in this group lack vocal
slits and have either large, rectangular, or bifid prepollices.
_Plectrohyla hartwegi_ differs from all of these species, except
_pycnochila_, by having a tuberculate, instead of a smooth, dorsum, and
_hartwegi_ differs from _pycnochila_ by having a bifid, instead of a
rectangular, prepollex.

_Remarks._--The known distribution of _Plectrohyla hartwegi_ includes
three localities at elevations of 1000 to 2050 meters in the Sierra
Madre of Chiapas and extreme eastern Oaxaca. The specimen from Paraje El
Triunfo was found in a rocky stream in cloud forest at an elevation of
2050 meters. One _Plectrohyla sagorum_ was obtained from the same
stream.

Eizi Matuda sent the holotype to the late Dr. Norman Hartweg, who
recognized that the specimen was unique but was reluctant to name the
species on the basis of a single specimen. Now that two additional
specimens are available, it seems appropriate to associate Hartweg's
name with this new species of _Plectrohyla_, a genus that Hartweg first
adequately defined.

LITERATURE CITED

ADLER, K.
1965. Three new frogs of the genus _Hyla_ from the Sierra
Madre del Sur of Mexico. Occas. Papers Mus. Zool. Univ.
Michigan, 642:1-18, pl. 1, December 16.

DUELLMAN, W. E.
1960. Synonymy, variation, and distribution of _Ptychohyla
leonhardschultzei_ Ahl. Studies of American hylid frogs, IV.
Herpetologica, 16:191-197, September 23.

1964. A review of the frogs of the _Hyla bistincta_ group.
Univ. Kansas Publ. Mus. Nat. Hist., 15:469-491, March 2.

1965. Frogs of the _Hyla taeniopus_ group. Copeia,
2:159-168, June 25.

STARRETT, P.
1966. Rediscovery of _Hyla pictipes_ Cope, with description
of a new montane stream _Hyla_ from Costa Rica. Bull. South.
California Acad. Sci., 65 (1):17-28, March.

_Transmitted July 11, 1967._

[Illustration: PLATE 17
Upper figure, _Hyla xanthosticta_ (KU 103772);
lower figure, _Hyla pseudopuma infucata_ (KU 101770). x 2.]

[Illustration: PLATE 18
Upper figure, _Hyla pellita_ (KU 100973);
middle figure, _Hyla pellita_ (KU 100970);
lower figure, _Hyla siopela_ (KU 100977). x 2.]

[Illustration: PLATE 19
Upper figure, _Hyla altipotens_ (KU 101