20, SYNOPSES AND DESCRIPTIONS. 
maxillary tooth longer, grooved. Crown-shields regular, Rostral broad, 
low, reaching the top of the snout. Internasals much smaller than pre- 
frontals. One preocular, not in contact with the frontal. Postoculars 
three (2—3). Loreal elongate. Labials eight, fourth and fifth in orbit. 
Two temporals in contact with the oculars. Scales smooth, in 19 rows, 
medial rather larger. Anal entire. 
Yellowish in alcohol, reddish in life, with thirty or more black rings— 
more or less complete—encircling the body. The intervals on the back 
are of varying width, reddish-white, and spotted with black. A dark spot 
on the crown, somewhat broken by lighter streaks on the edges of the 
plates. Belly yellowish, black bands often broken or incomplete, Central 
and South America. 
DENDROPHINAE. 
Tree snakes. Slender, elongate; head very distinct from the neck, nar- 
row, long, depressed, snout prominent; tail not distinct from the body, very 
slender. Eye moderate to large, pupil round. Nostrils small, lateral. 
Posterior upper maxillary teeth longer, grooved or smooth. Scales long, 
narrow, in 15 to 21 rows. Ventrals commonly with a slight keel at the 
side of the abdomen. Subcaudals in two rows. Tropics of both conti- 
nents. 
Posterior upper maxillary teeth longer, smooth; 
scales smooth or keeled LEPTOPHIS. 
Posterior maxillary teeth longer, grooved behind; 
scales smooth OXYBELIS. 
LEPToruis. 
Bell, 1825. 
Very slender, long; head long, narrow, depressed, distinct from the 
slender neck. Snout produced beyond the lower jaw. Eye large, pupil 
round. Postoculars 2—3. Abdomen slightly keeled at the sides. Post- 
maxillary teeth longer, smooth. Scales in 15 to 19 rows, smooth or keeled, 
Subcaudals in two rows. 
LEPTOPHIS MEXICANUS. 
LepropHis Mexicanus Duméril & Bibron, 1854, Erp. Gén. VII, 536. 
Two postoculars. Loreal present. Labials eight. Scales in 15 rows, 
carinate on trunk and tail. Ventrals 157--169. Anal bifid. Subcaudals 
138—154 pairs. Mexico. (Irom descr.) 
