20 SYNOrSES AXD DESCRIPTIONS. 



maxillary tooth longer, grooved. Crown-shields regular. Rostral broad, 

 low, reaching the top of the snout. Intcrnasals much smaller than pre- 

 frontals. One ]n'eocular, not in contact with the frontal. Po.'^toeulars 

 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, somewdiat 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, jiupil 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 Leptopiiis. 



Posterior maxillary teeth longer, grooved behind ; 



scales smooth Oxybelis. 



Leptophis. 



Bdl, 1825. 



Very slender, long; head long, narrow, depressed, distinct from the 

 slender neck. Snout produced beyond the lower jaw. Eye large, puj)il 

 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. 



LEPTnpiit.s MEXICANUS DuMeril (fc BihroH, isr)4, Krp. Ci'n. VII, 536. 



Two postoculars. Loreal present. Labials eight. Scales in 15 rows, 

 carinate on trunk and taih Ventrals 157 — 1G9, Anal l»ifid. Subcaudals 

 138 — 154 pairs. Mexico. (From descr.) 



