Diagnosis.—Large frogs, males 22.1-33.2 mm. snout-vent, females 26.8-39.6 mm. snout-vent length; vocal slits lacking in males; digital tips greatly expanded (more than twice the width of digit); first finger shorter than second; skin of dorsum pustular, that of venter smooth; diameter of tympanum in males 61.1-87.2 per cent that of eye, 49.5-72.1 per cent in females; dorsum tan with large or small spots and blotches; limbs banded; interorbital bar or triangle present.
Remarks.—I have applied Baird's Batrachyla longipes to the frog Taylor (1940d) called Syrrhophus latodactylus because the color pattern ([Fig. 13]) predominant in the southern part of the range agrees with that described (figured) for Batrachyla longipes.
The color pattern of individuals in the southern part of the range of this species consists of large spots or blotches, whereas in the northwestern part the pattern is made up of smaller spots. In the northeastern part of the range, the pattern is more reduced and tends to consist of heavy flecking. The interorbital bar is narrower in specimens from Nuevo León and Tamaulipas and is triangular in specimens from Hidalgo and Queretaro.
The status of the name Batrachyla longipes is currently that of a nomen dubium (Lynch, 1963). At that time, I was unaware of the geographic variation in color pattern in Syrrhophus latodactylus.
The exact type-locality of Batrachyla longipes is not known. If it is 40 Leagues north of México City, the locality would be in an area where the species has a blotched instead of a flecked or spotted pattern. No justifiable evidence was presented to place Batrachyla longipes in Eleutherodactylus instead of Syrrhophus. Barbour (1923) and Kellogg (1932) associated another species (E. batrachylus) with longipes. Taylor (1940a) noted this as a case of misidentification and corrected the error but left longipes in the genus Eleutherodactylus. Lynch (1963) noted several points of morphological agreement between Syrrhophus and B. longipes but did not place longipes in Syrrhophus.
Baird's (1859) figures of the holotype do not illustrate prevomerine teeth, but according to Cope (1866) they were present in the holotype. The digital tips of the frog in the figure are somewhat narrower than those typically seen in S. latodactylus. If the specimen was slightly desiccated, as possibly was the case, the digits would appear narrower. There is no evidence contrary to placing Syrrhophus latodactylus in the synonymy of Batrachyla longipes.
Fig. 13: Dorsal views of Syrrhophus longipes illustrating geographic variation in pattern (left, TCWC 12179, ×1.5; right, KU 92572, ×1.8); side of head (TCWC 10966, ×6).
Application of Baird's name Batrachyla longipes to the species of frog heretofore called Syrrhophus latodactylus poses one serious problem. Batrachyla longipes is the type-species (by original designation) of the genus Epirhexis Cope, 1866, which has priority over Syrrhophus Cope, 1878. If Batrachyla longipes is left in the status of a nomen dubium, Epirhexis can be forgotten, for the two names are tied together. However, since it seems almost certain that Batrachyla longipes and Syrrhophus latodactylus are conspecific, the former name should not be left as a nomen dubium. Epirhexis never came into general usage (Cope cited the name four times, but no one else has used it), whereas Syrrhophus is well established in the zoological literature. It would serve only to confuse the literature to adhere strictly to the Law of Priority and replace Syrrhophus with Epirhexis. Therefore, Syrrhophus is used in this paper, even though Epirhexis has priority. A request for the suppression of Epirhexis Cope, 1866, has been submitted to the International Commission of Zoological Nomenclature (Lynch, 1967).