184, HoMALOCRANIUM. 217 
Tantilla pallida, Cope, Proc. Amer. Philos. Soc. xxiv. 1887, 
p. 56, from Matto Grosso, Brazil, appears to agree in every respect 
with H. melanocephalum, except in having the first lower labial 
separated from its fellow by the symphysial. This is probably 
merely an individual variation, as the condition described by Cope 
is nearly attained by two of the specimens from Para in the 
Museum. 
2. Homalocranium annulatum. 
Tantilla annulata, Boettg. Zool. Anz. 1892, p. 419. 
Homalocranium annulatum, Giinth. Biol. C.-Am., Rept. p. 150 
(1895). | 
The description does not give any structural characters by which 
this form may be distinguished from H. melanocephalum, but the 
coloration is very different. Head black; snout to the middle of 
the preefrontals yellow; fifth upper labial yellow ; two narrow yellow 
collar-bars, each broadly edged with black, the anterior crossing 
the extremity of the parietal shields ; anterior third of body dark 
grey-brown, with alternating yellow, black-edged transverse spots 
or bars extending from the vertebral line to the outer ends of the 
ventrals ; lower parts uniform yellow. 
Total length 484 millim.; tail 99. 
Nicaragua. 
3. Homalocranium trilineatum. 
sho Sls trilineatus, Peters, Mon. Berl. Ac. 1880, p. 221, pl.—. 
g. 2, 
Homalocranium teniatum, Bocourt, Miss. Sc. Mex., Rept. p. 587, 
pl. xxxvii. fig. 3 (1888); Giinth. Biol. C.-Am., Rept. p. 151 (1895). 
eee F, Miill. Verh. Nat. Ges. Basel, vii. 1885, 
Tantilla teeniata, Cope, Bull. U.S. Nat. Mus. no. 32, 1887, p. 88. 
Eye half as long as the snout. Rostral much broader than deep, 
visible from above; internasals half as long as the prefrontals ; 
frontal hexagonal, obtuse-angled in front, acute-angled behind, once 
and a half as long as broad, longer than its distance from the end 
of the snout, shorter than the parietals; nostril between two nasals, 
the posterior in contact with the preocular ; two postoculars ; tem- 
porals 1+1; eight upper labials, third and fourth entering the eye; 
first lower labial separated from its fellow, the symphysial being in 
contact with the anterior chin-shields; four lower labials in contact 
with the anterior chin-shields, which are longer than the posterior. 
Scales in 15 rows. Ventrals 145-163; anal divided; subcaudals 
68-69. Brown above, with three yellowish, dark-edged longitudinal 
lines ; a yellowish cross-band on the occiput, not connected with 
the longitudinal lines ; a yellowish spot on each side of the head 
behind the eyes ; lower parts whitish. 
Total length 275 millim. ; tail 65. 
Guatemala, Honduras, 
a. 2 (V.163; C.69). Bonacca Id., Honduras. F. B poe Esq. 
