184 COLUBRID. 
5. Urotheca bicincta. 
Coluber bicinctus, Hermann, Obs. Zool. p. 276 (1804). 
Elaps schranckii, Wagi. in Spiv, Serp. Bras, p. 1, pl. i. (1824). 
Xenodon bicinctus, Schleg. Phys. Serp. ii. p. 95 (1837). 
Liophis bicinctus, Dum. § Bibr. vii. p.716 (1854) ; Giinth. Cat. p. 43 
1858). 
ae bicinctus, Jan, Arch. Zool. Anat. Phys. ii. 1863, p. 321. 
Eye rather small; snout short, rounded. ostral much broader 
than deep, just visible from above ; internasals as long as or shorter 
than the prefrontals ; frontal as long as broad or a little longer, 
as long as or shorter than its distance from the end of the 
snout, shorter than the parietals ; loreal nearly as long as deep or 
longer than deep; six scales surround the eye in addition to the 
supraocular, the labials being excluded from the eye; temporals 
242 or 3438; eight or nine upper Jabials; chin-shields short. 
Seales in 19 or 21 rows. Ventrals 168-192; anal entire; sub- 
caudals 69-94. Reddish brown above, with black annuli arranged 
in pairs, each pair bordered with yellow in front and behind; a 
black band behind the eye, confluent with another across the occiput 
and descending to the gular region; belly yellow, spotted with 
black ; tail with complete annuli. 
Total length 1950 millim. ; tail 650. 
Guianas, Brazil. 
a. d (Se. 19; V.171; C. 90). British Guiana. Demerara Museum. 
6. 9 (Sc. 21; V.176; C. 72). S. America. 
ce. Yg. (Sc.19; V.169;C.87). S. America. Zool. Soe. 
83. TRIMETOPON. 
Trimetopon, Cope, Proc. Amer. Philos. Soc. xxii. 1885, p. 177. 
Maxillary short, with 12 teeth, which gradually increase in length 
- to the last ; mandibular teeth subequal. Head scarcely distinct from 
neck ; eye small, with round pupil; a single prefrontal. Body elon- 
gate, cylindrical ; scales smooth, with very indistinct apical pits, in 
15 rows; ventrals rounded. Tail moderate; subcaudals in two rows. 
Central America. 
1. Trimetopon gracile. 
Ablabes gracilis, Giinth. Ann. § Mag. N. H. (4) ix. 1872, p. 18, pl. iii. 
fig. D. 
Trimetopon gracile, Cope, Proc. Amer. Philos. Soc, xxii, 1885, p. 177. 
Snout short, rounded. Rostral more than twice as broad as deep, 
scarcely visible from above; internasals small, much broader than 
deep ; prefrontal nearly twice as broad as deep; frontal once and 
one third to once and a half as long as deep, a little longer than its 
distance from the end of the snout, much shorter than the parietals ; 
loreal small, longer than deep; one pre- and one postocular ; 
temporals ]1+1; seven or eight upper labials, third and fourth or 
fourth and fifth entering the eye; four or five lower labials in 
