SNAKES. 113 



c, d. Adult. Khasya. Presented by Dr. Hooker. 



e,f. Adult: bad state. Sikkim. Presented by Dr. Hooker. 



g. Adult. Affgbanistan. 



a, b, present strong keels only on the pair of vertebral rows ; 

 c-g, weaker keels on four dorsal rows. 



Fatn.V. DRYADID^. 



Body generally elongate, not much compressed (except in a 

 few species) ; tail proportionally elongate, slender, not distinct 

 from trunk, tapering ; head moderate, or with elongate muzzle, 

 distinct from neck; shields of head regular, posterior frontals 

 truncated behind, loreal sometimes wanting; generally one an- 

 terior and two posterior oculars; scales elongate, lanceolate; 

 subcaudals two-rowed ; eye rather large, pupil round. 



No longer tooth in front, or in the middle of the maxillary bone. 



Herpetodryas, Schlegel, Ess. ii. p. 173. Isodontiens, part., 

 Dromicus, Dryophylax, Hum. cy- Bibr. 



Synopsis of the Genera. 



1. Herpetodryas. Body not much compressed; two nasals; 



teeth equal, smooth. America. 



2. Cyclophis. Body rounded ; one nasal ; teeth equal, smooth. 



North America; East Indies. 



3. Dryocalamus. Body much compressed; one nasal; teeth 



equal, smooth. 



4. Gonyosoma. Body much compressed; two nasals; teeth 



equal, smooth. East Indies. 



5. Philodryas. Hinder maxillary teeth grooved. South 



America ; Madagascar. 



fi. Dromicus. Hinder maxillary tooth longest, not grooved, 

 separated by an interspace. "West Indies ; South America. 



1. Herpetodryas, Boie. 



Teeth equal in length, none grooved. Body generally very 

 slender, rounded or slightly compressed; head elongate, with 

 flat crown, distinct from neck ; one loreal ; two nasals ; one an- 

 terior, two posterior oculars. Scales elongate, in not more than 

 nineteen rows. Eye large. Warmer parts of America. 



Herpetodryas, Boie, Isis, 1827; Wagl. Syst. Amph. p. 180; 



