66 coLTjBErDa:. 



c-j?. Yg. (Sc. 23, 21 ; V. Ventanas, Durango. Hr. A. Forrer [C.]. 



223,220; C.70,72). 



e-/. Yg.(Sc. 23,23 ;V. S.Mexico. F. D, Godman, Esq, 



236,214; C.72,72). [P.]. 



3. Trimorpliodoii lyrophanes. 



Lycodon lyrophanes. Cope, Proc. Ac. Philad. 1860, p. 343. 

 Ti-imorphodon lyrophanes, Cope, Proc. Ac. Philad. 1861, p. 297, and 



Proc. Amer. Philos. Soc. xi. 1869, p. 152. 

 Sibon biscutatum, part., Garm. N. Am. Rept. p. 16 (1883). 



Eostral broader than deep, visible from above ; praefrontals 

 broader than long ; two loreals ; two praeoculars and a snbocular, the 

 upper prseocular not in contact with the frontal ; three postoculars ; 

 .nine upper labials, fourth and fifth entering the eye ; anterior chin- 

 shields the longer. Scales in 21 rows. Ventrals 236 ; anal 

 divided; subcaudals 70. Light grey above; snout crossed by an 

 indistinct ashy band ; a lyre-shaped brown marking on the head ; 

 back with deep brown spots disposed in pairs ; an irregular series 

 of lateral spots and another extending on the ends of the ventral 

 shields ; under surface whitish. 



Total length 710 miUim. ; taU 110. 



Lower California, Arizona. 



4. Trimorphodon tau. 



Trimorphon tau, Cope, Proc. Amer. Philos. Soc. xi. 1869, p. 152, and 

 xxiii. 1886, p. 286. 



Snout projecting considerably beyond the mouth. Eostral some- 

 what produced behind ; iatemasals about one fourth the size of the 

 praefrontals, which are as long as wide ; frontal as long as the 

 parietals ; three loreals ; two prseoculars and a subooular ; three 

 postoculars ; temporals 2 + 3 ; six or seven upper labials, fourth 

 and fifth entering the eye. Scales in 23 rows. Grey above, with 

 black rhombs which extend to the ventral shields by their lateral 

 angles ; head black as far as the middle of the parietal shields, 

 with two lateral ear-shaped prolongations on the latter; a pale 

 X-shaped mark, the longitudinal limb on the snout, the transverse 

 limb between the eyes. 



Total length 236 miUim. ; tail 36. 



Isthmus of Tehuantepec, Mexico. 



146. LYCOGNATHUS. 



Lycodon, part., £oie, Isis, 1827, p. 621 ; ScMeg. Phys. Serp. ii. p. 104 



(1837). 

 Lycognathus, part., Dtcm. 8r Bihr. Mim. Ac. Sc. xxiii. 1853, p. 496 



and Erp. Q6n. vii. p. 916 (1854). 

 Siphlophjs, Cope, Proc. Ac. Philad. 1861, p. 297. 

 Oxyrhopua, part., Jan, Elenco sist. Ofld. p. 92 (1863). 



Maxillary teeth 14 to 16, anterior much longer than the posterior, 



