184, HOMALOCRANIUM. 227 
very prominent. Rostral large, broader than deep, its upper 
portion measuring about two thirds its distance from the frontal ; 
internasals about half as long as the preefrontals ; frontal hexagonal, 
obtuse-angled in front, acute-angled behind, a little longer than 
broad, longer than its distance from the end of the snout, 
shorter than the parietals; nostril in a divided or semidivided 
nasal, which is in contact with or narrowly separated from the 
preocular; latter exceptionally divided; one or two postoculars * ; 
temporals 1+1; seven upper labials, third and fourth entering 
the eye; first lower labial in contact with or separated from its 
fellow ; four lower labials in contact with the anterior chin-shields, 
which are longer than the posterior. Scales in 15 rows. Ventrals 
121-153; anal divided; subcaudals 42-58. Pale brown above, 
head dark brown or black ; lower parts white. 
Total length 260 millim.; tail 50. 
Lower California to Western Texas and North Mexico. 
a-c,d.. g (V.127,126; C.?, Duval Co., Texas. W. Taylor, Esq. [P.]. 
58), 9 (V. 153; 0. 45), & 
yg. (V. 121; ©. 57). 
22. Homalocranium calamarinum. 
Tantilla calamarina, Cope, Proc. Ac. Philad. 1866, p. 320, and Journ. 
Ac. Philad. (2) viii. 1876, p. 148. 
—— bimaculata, Cope, Journ. Ac. Philad. (2) viii. 1876, p. 148. 
Homalocranium bimaculatum, Bocourt, Miss. Sc. Mex., Rept. p. 580, 
pl. xxxvi. fig. 6 (1883); Giinth. Biol. C-Am., Rept. p. 154 
(1895). 
Eye not half as long as the snout, which is prominent. Rostral 
broader than deep, well visible from above; internasals about half 
as long as the preefrontals ; frontal hexagonal, slightly longer than 
broad, longer than its distance from the end of the snout, shorter 
than the parietals; nostril between two nasals, the posterior in 
contact with or narrowly separated from the preocular; one post- 
ocular; temporals 1+1, the anterior sometimes separated from the 
postocular by the contact of the parietal and fifth labial; six upper 
labials, third and fourth entering the eye; first lower labial sepa- 
rated from its fellow by the symphysial; four lower labials in 
contact with the anterior chin-shields, which are longer than the 
posterior. Scales in 15 rows. Ventrals 119-132; anal divided; 
subcaudals 27-35. Pale brown above, with three brown longi- 
tudinal lines, the vertebral extending to the head, which is dark 
brown, and dividing a yellowish occipital blotch; end of snout 
yellowish ; lower parts white. 
Total length 195 millim. ; tail 25. 
Mexico. 
* Two of the specimens in the Collection have one postocular on each side ; 
the third has one on the left side and two on the right; whilst in the fourth 
the postocular is fused with the supraocular. 
Q2 
