145. .TRIMORPHODON. 55 
a. é (Se. 25; V. 251; Lanquin, Guatemala, 0. Salvin, Esq. [C.]. 
. 87 
k. Hgr. 9 (Sc. 27; V. Guatemala. O. Salvin, Esq. [C.], 
253; C. 81). 
l. 2 (Sc. 27; V. 263; Nicaragua. 
C. 79). 
3 c— 25; V.259; Panama. Capt. J. C. Dow [P.]. 
. 89). 
n. Hgr. 2 (Sc. 25; V. CO. America. Haslar Collection. 
256; C. 77). 
o. Skull. San Ramon, Mexico. Dr. A. C. Buller (C.]. 
2. Trimorphodon upsilon. 
Trimorphodon upsilon, Cope, Proc. Amer. Philos, Soc. xi. 1869, 
P. oe and xxili. 1886, p. 286; Giinth. Biol. C.-Am., Rept. p.175 
895). 
Digsas biscutata, var. latifascia, Peters, Mon. Berl, Ac. 1869, p. 877. 
Eteirodipsas biscutata, Jan, Icon. Gén. 39, pl. i. fig. 3 (187 2). 
Trimorphodon collaris, Cope, Journ. Ac. Philad. (2) viii. 1876, p, 181, 
and Proc, Amer. Philos. Soc. xxiii. 1886, p. 286. 
Sibon biscutatum, part., Garm. N. Am. Rept. p. 16 (1883). 
upsilon, Garm. J. ¢. p. 184. 
? Trimorphodon vilkinsonii, Cope, Proc. Amer. Philos. Soc. xxiii. 
1886, p. 285. 
Rostral broader than deep, the portion visible from above 
measuring one fourth to one third its distance from the frontal; 
internasals much shorter than the preefrontals, which are nearly as 
long as broad; frontal once and a half to once and two thirds as 
long as broad, as long as or a little longer than its distance from the 
end of the snout, as long as the parietals; two or three loreals; 
two preoculars and a subocular; upper preocular in contact with 
or narrowly separated from the frontal; two or three postoculars ; 
temporals 2+ 2, 2+3, or 3+3; eight or nine upper labials, fourth 
and fifth entering the eye; five or six lower labials in contact 
with the anterior chin-shields, which are longer than the posterior. 
Scales in 21 or 23 rows. Ventrals 205-236; anal divided; sub- 
caudals 61-72. Pale grey-brown above, with dark, black-edged 
cross-bars narrowing on the sides and descending to the ends of the 
ventrals; head dark brown above, pale greyish on the occiput, 
usually with a light cross-bar between the eyes; a V-shaped light 
marking sometimes present on the parietal shields, embracing the 
frontal; whitish beneath, more or less mottled with dark and with 
dark spots on the sides. In the young the dark bars are much 
wider, separated by narrow whitish interspaces, and they may form 
complete annuli. 
Total length 660 millim. ; tail 120. 
Mexico. | 
a, & (Sc. 283; V.217; La Cumbre de los Dr. A.C. Buller [C.]. 
C. 71). Arrastrados, Jalisco. 
b. a (Ge. 21; V.205; Jalapa. Mr. Hoege [C.]. 
61). 
