50 BULLETIN 18 7, UNITED STATES NATIONAL MUSEUM 



3. Dorsal surface with spots ; ventrals 150 to 156, caudals 55 to 65 sanniolus 



Body and tail with complete bands; ventrals and caudals more numerous, 



185 to 200, 98 to 126, respectively dimidiatus 



4. At least two infralabials in contact behind mental 6 



One infralabial in contact behind mental 5 



5. "Vertebral scales strongly enlarged ; anterior chin shields little if any longer 



than broad elegans 



Vertebral scales somewhat enlarged brevis 



6. "Vertebral scales strongly enlarged maxillaris 



Vertebral scales somewhat enlarged brevifacies 



DIPSAS BREVIFACIES (Cope) 



Tropidodipsas brevifacies Cope, Proc. Acad. Nat. Sci. Philadelphia, vol. 18, 



1866, p. 127. 

 Leptognathus brevifacies Mocquabd, Mission sdentifique au Mexique et dans 



I'Am^rique centrale, Rept., livr. 16, 1908, pp. 891-892, pi. 72, fig. 7. 

 Sibon brevifacies Smith, Proc. U. S. Nat. Mus., vol. 93, 1943, p. 470. 

 Dipsadomorus fasciatus Bocourt, Bull. Soc. Philom. Paris, ser. 7, vol. 8, 1884, pp. 



135-136 (type locality, Yucatan; type in Mus. Hist. Nat. Paris). 

 LeptognatJius torquatus Oopb, Proc. Amer. Philos. Soc, vol. 22, 1884 (1885), p. 



172 (substitute name for Leptognathus fasciatus (Bocourt), preoccupied). 



ry;?e.— U.S.N.M. No. 24886. 



Type locality. — Yucatan. 



Range. — The northern and eastern portions of the Yucatan Penin- 

 sula (only definite localities in Mexico are several in Yucatan and 

 Ciudad del Carmen, Gampeche). 



DIPSAS BREVIS (Dnmeril, Bibron, and Dnmeril) 



Leptognathus brevis Dumkril, Bibbon, and Dumeril, Erpetologie gen^rale, vol. 

 7, pt. 1, 1854, pp. ^IQ-All. — MocQUARD, Mission scientiflque au Mexique et 

 dans I'Amerique centrale, Rept., livr. 16, 1908, p. 889. 



Type. — Lost. 



Type locality. — Mexico. 



Range. — Unknown. 



DIPSAS DIMIDIATUS (Gunther) 



Leptognathus dimidiata Gxjnther, Ann. Mag. Nat. Hist, ser. 4, vol. 9, 1872, p. 31. 

 Mesopeltis dimidiatus Gxjnther, Biologia Centrali-Americana, Rept., 1894, pp. 



143-144, pi. 51, figs. A, B (in color). 

 Sibon dimidiatus Smith, Proc. U. S. Nat. Mus., vol. 93, 1943, p, 470. 

 Petalognathus multifasciaius Bocourt, Bull. Soc. Philom. Paris, ser. 7, vol. 8, 



1884, p. 139 (type locality, Verapaz, Guatemala; type in Paris Mus.). 



Type.— Brit. Mus. Nat. Hist. No. 6(3-4-16, 6. 



Type locality. — Mexico. 



Range. — Atlantic foothills of Chiapas and Guatemala ^ (no definite 

 localities in Mexico are recorded ; it is known, however, from Piedras 

 Negras, Guatemala). 



^ It is inferred that Dipsas grandocuUs (Miiller, Verh. Naturf. Ges. Basel, vol. 8, 1887, 

 pp. 271-272, pi. 1, fig. 2 ; type locality, Mazatenango, Guatemala) may be a valid species, 

 since it is from Tacific slopes. It may well occur in adjacent Chiapas. 



