56 COLUBRID, 
e-d. Yg. (Sc.28,21;V. | Ventanas, Durango. Hr. A. Forrer [C.]. 
228, 220; C. 70,72). 
e-f. Yg. (Sc. 23,23; V. §&. Mexico. F. D. Godman, Esq. 
236, 214; C. 72,72). [P.]. 
3. Trimorphodon lyrophanes. 
Lycodon i grams: Cope, Proc. Ac. Philad. 1860, p. 343. 
Trimorphodon lyrophanes, Cope, Proc. Ac. Philad. 861, p. 297, and 
Proc. Amer. Philos. Soc. xi. 1869, p. 152. 
Sibon biscutatum, part., Garm. N. Am. Rept. p. 16 (1883). 
Rostral broader than deep, visible from above; prefrontals 
broader than long ; two loreals; two preoculars and a subocular, the 
upper preocular 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 millim.; tail 110. 
Lower California, Arizona. 
4. Trimorphodon tau. 
Trimorphon tau, care Proc, Amer. Philos, Soc. xi. 1869, p. 152, and 
xxiii. 1886, p. 286, 
Snout projecting considerably beyond the mouth. Rostral some- 
what produced behind ; internasals about one fourth the size of the 
preefrontals, which are as long as wide; frontal as long as the 
parietals ; three loreals; two preoculars and a subocular; three 
postoculars ; temporals 243; 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 
i-shaped mark, the longitudinal limb on ite snout, the transverse 
limb between the eyes, 
Total length 236 millim.; tail 35. 
Isthmus of Tehuantepec, Mexico. 
146, LYCOGNATHUS. 
tee part., Bote, Isis, 1827, p. 521; Schleg. Phys. Serp. ii. p. 104 
(188 
Lyco op part., Dum. § feeds Mém. Ac, Se, xxiii, 1858, p, 495 
Erp, Gén. vii. p. Ya eae 
Siphlophis, Cope, Proc. Ac ilad. 1861, p. 297. 
Oxyrhopus, part., Jan, Elenco sist. Ofid. p. 92 (1863). 
Maxillary teeth 14 to 16, anterior much longer than the posterior, 
