18 SYNOPSES AND DESCRIPTIONS. 



SiBON TORQUATUM. 



Leptodeira torquata Gi'mtJier, 1860, Ann. <& Mag. Nat. Hist., pi. X, 169. 



Posterior maxillarv tootli larger, separated by an interspace. Scales in 

 21 rows. Ventrals 174. Anal bifid. Subeaudals 41—56. Total length 

 16 in. 51.; tail 3 inches. Total length 17 in. 51.; tail 2 in. 31. 



Brownish-grey, with a vertebral series of brown spots, some of which 

 are confluent into a zigzag band ; neck with a white collar, behind which 

 there is a large brownish-black blotch. Hab. Nicaragua ; Island of Laguna. 

 (From Griinther.) 



SiBON DISCOLOR. 

 Leptodeika discolor Gilnthci; 1860, Pr. Zxjl. Soc. Lond., 317. 



Posterior maxillary tooth larger, in a continuous series with the other 

 teeth, not grooved. Scales in 19 rows, smooth, rhombic, those of the sides 

 similar to those of the back. Yentrals 179 — 182. Anal bifid. Subeaudals 

 87—88. Total length 21 in. 1 1. ; tail 6 in. 



Dirty white, with numerous black cross-liands extending on to the ven- 

 tral plates; belly uniform whitish. Fifty-one to fifty-four black bands cross 

 the trunk and extend to the edge of the belly; they are broader than the 

 interspaces between, and become interrupted and spot-like on the tail. 

 Upper part of head brown, with a whitish collar behind the occipitals. 

 Separated from »b'. a/mulatum by the teeth. Hab. Oaxaca, Mex. (From 

 Gunther.) 



SCYTALINAE. 



Moderate, cylindrical to subcylindrical ; head distinct from the neck, 

 broad Ijehind, crown flat; tail medium, ta])ering. Eye medium, 2)upil 

 oblong or elliptical. Crown-shields nine. N'asal generally divided. A 

 lorcfil. Preoculars one to two. Postoculars two. Posterior maxillary 

 teeth longer, grooved. Scales smooth, in 17 to 19 rows, occasionally the 

 vertebral series larger. Anal entire. Subeaudals simple or bifid. 



OXYRHOPUS. 



War/kr, 1880. 



Elongate and subcylindrical to slender and slightly compressed; head 

 moderate, a little larger than the neck, depressed, muzzle rather broad, 

 crown flat; tail short to moderate. Eye medium, ]iu[)il elliptical, erect. 



