SNAKES. 23 



Synopsis of the Genera. 



1. Simotes. Rostral conical, protruding, extending backwards 

 between tbe anterior frontals. Scales in seventeen or nine- 

 teen rows. East Indies; North America ; Algiers. 



_'. Ablabes. Rostral moderate. All teeth equal. All scales 

 smooth. United States; Africa; Asia. 



3. Trach ischium. Scales of the ischiadic region provided 



with granulated keels. Sikkim. 



4. Psammophylax. Rostral rounded, not protruding, with 



a long posterior process. South Africa. 



5. Tachymenis. Either two anterior oculars and a separate 



loreal, or loreal united with lower ocular. Posterior max- 

 illary tooth grooved. South Europe; Chili. 



6. Coronella. Rostral moderate ; one anterior ocular. Pos- 



terior maxillary tooth either smooth, longer, and in a con- 

 tinuous row with the anterior ones, or grooved. Almost 

 every part of the globe. 



7- Liophis. Rostral moderate; posterior maxillary tooth 

 longest, smooth, and separated from the anterior ones by 

 an interspace. Warmer parts of America. 



8. Erythrolamprus. Body encircled by black rings. Pos- 



terior maxillary tooth grooved. South America. 



9. Hypsirhynchus. Forehead concave; muzzle pointed and 



raised. Barbadoes. 



1. Simotes, Dum. Sf Bibr. 



Head short, conical, not distinct from neck ; rostral shield 

 as in Oligodon, rather flat in front, pointed behind, and far 

 produced backwards between the anterior frontals ; two nasals, 

 nostril between ; one anterior ocular (in one species three], two 

 posterior oculars. Scales smooth, in seventeen or nineteen rows 

 (Dumeril's S. trinotatus twenty-one?). Posterior maxillary 

 teeth longest, smooth. Crown of head with regular, generally 

 arrow-shaped marks. East Indies. (North America; Algiers.) 



Simotes, Dum. Sf Bibr. vii. p. (>24. Heterodon, sp., Dum. fy 

 Bibr. vii. p. 77$. Coronella, sp., Schleg. Ess. ii. p. 77, 79, and 

 Heterodon, sp., id. p. 102, and Xenodon, sp., id. p. 90. Rhino- 

 stoma, sp., Holbrook, N. Amer. Her pet. iii. p. 125 ; Baird, 

 Girard Catal. p. 118. Coronella, sp., Boie, Isis, 1827, p. 539. 

 Elaps, sp., Coluber, sp., auct. prior. 



