4 BULLETIN 194, UNITED STATES NATIONAL MUSEUM 



KEY TO MEXICAN GENERA OF CAECILIIDAE 



1. Eye visible; tentacle only slightly nearer eye than nostril; primary (97-110) 

 and secondary (51-80) rings reduced in number; stout; total length/ 



diameter ratio 14-26 Dermophis (p. 4) 



Eye invisible or not, completely or partially encased under bone; tentacle 

 very close to eye; primaries (119-137) and secondaries (98-122) more 

 numerous; generally more slender; total length/diameter ratio 

 24-40 Gymnopis (p. 5) 



Genus DERMOPHIS Peters « 



Dermophis Peters, Monatsb. Akad. Wiss. Berlin, 1879, p. 937.— Dunn, Bull. 

 Mus. Comp. Zool., vol. 91, 1942, pp. 461-479 (part). 



Genotype. —Dermophis mexicanus Dum^ril and Bibron (by subse- 

 quent designation, Noble, Bull. Amer. Mus. Nat. Hist., vol. 49, 1924, 



p. 305). 



i^an^e.— Veracruz and Guerrero, Mexico, to Ecuador. 



Species.-— Y\Y& forms are recorded, three of which are races of 

 Z?. mexicana; one enters Mexico. 



DERMOPHIS MEXICANUS MEXICANUS (Dumgril and Bibron) 



Siphonops mexicanus DumiSril and Bibron, Erp^tologie g6n6rale, vol. 8, 1841, 



pp. 284-5. 

 Dermophis mexicanus Peters, Monatsb. Akad. Wiss. Berlin, 1879, p. 937, fig. 6. 

 Dermophis mexicanus mexicanus Dunn, Proc. New England Zool. Club, vol. 10, 



1928, pp. 74-75, pi. 5. 

 Gymnopis mexicanus mexicanus Dunn, Bull. Mus. Comp. Zool., vol. 91, 1942, 



pp. 473-476. 



Type.— Mns. Hist. Nat. Paris No. 5c {fide Dunn). 



Type locality. — Mexico. 



Range.— The Atlantic coast from central Veracruz southeastward 

 to the Isthmus of Tehuantepec and perhaps to Yucatdn; and on the 

 Pacific coast from the Isthmus southeastward to western Nicaragua. 

 In Mexico known from Veracruz: Cuatotolapam, Veracruz; Oaxaca: 

 Tehuantepec, Barrio; Tabasco: Teapa; Chiapas: La Zacualpa, Soco- 

 nusco, Escuintla; Yucatan: loc? (Duges). 



« In his revision of American caccilians, Dunn (Bull. Mus. Comp. Zool., vol. 91, 1942, pp. 437-540) unites 

 Dermophis and Gymnopis (under the latter name) because of the existence of apparently annectant forms. 

 The eye, visible and in an open orbit, is invariable in the three species of Dermophis but variable in visi- 

 bility and presumably in extent of enclosure by bone in the four species of Gymnopis. However, the posi- 

 tion of the tentacle (very near eye in Gymnopis, halfway between eye and nostril in Dermophis) does not 

 overlap, the extent of closure of the orbit probably does not overlap (not known for all forms), and finally 

 there is no indication that the present groupmgs of species under these two names are unnatural. For these 

 reasons we retain Dermophis. 



