Skin of dorsum and ventral surfaces of limbs, except thighs, smooth; skin of chin, belly, and ventral surfaces of thighs granular; thoracic fold present. Tongue nearly round, slightly notched behind, and barely free posteriorly; vomerine teeth 3-3, situated on posteroventral edges of small, transverse vomerine ridges between rather large triangular inner nares; no vocal slits. Color (in alcohol) of dorsal surfaces of head, body, and limbs dull grayish brown with indistinct scattered darker flecks; flanks grayish brown with cream-colored reticulations; posterior surfaces of thighs tan; chin cream-color, mottled with brown; belly creamy yellow; anal stripe cream-color. _Variation._--In addition to the specimen described above three others are known. One is a juvenile having a snout-vent length of 29.5 mm., and two are females having snout-vent lengths of 46.9 and 41.6 mm. Variation in structure and coloration between the four specimens is slight. In the females the tympani are partly visible and are about one-third the diameter of the eye; the chest is mottled with brown; the anal stripe extends laterally in the form of a row of cream-colored dashes and spots onto the posterodorsal surfaces of the thighs. _Remarks._--On the basis of the four specimens available for study, _Hyla pachyderma_ seems to be closely related to _Hyla crassa_ and _Hyla robertsorum_. In the _Hyla bistincta_ group, _Hyla pachyderma_ is unique in having enlarged nuptial spines. Taylor and Smith (1945:588) stated that the frogs were found on bushes and weeds beside a small, bounding stream near Pan de Olla. I have searched unsuccessfully for this species in the area around Pan de Olla and Tezuitlán. _Distribution._--This species is known only from a stream at an elevation of about 1600 meters on the Atlantic slopes of the Sierra Madre Oriental in central Veracruz (Fig. 4). Specimens examined.--VERACRUZ: Pan de Olla, south of Tezuitlán, Puebla, USNM 115026-9. #Hyla crassa# (Brocchi) _Cauphias crassus_ Brocchi, Bull. Soc. Philom. Paris, ser. 7, 1:130, 1877 [Holotype.--MNHN 6331 from "Mexico;" Adolphe Boucard collector]. _Cauphias crassum_ Brocchi, Études des batraciens de l'Amérique Centrale, p. 64, pl. 12, fig. 4, 1882. Díaz de León, Indice de los batracios que se encuentran en la República Mexicana, p. 21, June, 1904. Kellogg, Bull. U. S. Nat. Mus., 160:118-120, March 31, 1932. Taylor, Univ. Kansas Sci. Bull., 26:392, November 15, 1940. Rabb and Mosimann, Occas. Papers Mus. Zool. Univ. Michigan, 563:7, March 29, 1955. _Hyla crassa_, Boulenger, Catalogue Batrachia Salientia, 2nd. Ed., p. 396, February 1, 1882. Günther, Biologia Centrali-Americana, Reptilia and Batrachia, p. 281, September, 1901. Nieden, Das Tierreich, Amphibia, Anura 1, p. 248, June, 1923. Smith and Taylor, Bull. U. S. Natl. Mus., 194:86, June 17, 1948. Taylor, Amer. Mus. Novitates, 1437:20, December 7, 1949.