198 JOURNAL, R.A.S. (CEYLON). [VOL. XL 



FOItM. 



A = 24 Zambnis mucosus. 



Body of moderate length, more or less cylindrical ; belly 

 flat, more or less rounded ; head rarely very distinct 

 from neck, with a flat crown, and more or less depressed 

 muzzle ; tail cylindrical, tapering to a point. 



1. — Head elongate, distinct from neck; snout obtuse, 



slightly projecting. 24 Z. mucosus. 



2. — As in a 1 ; snout curved and prominent. 25 Z. fas- 



ciolatus. 



3. — As in a 1 ; snout not projecting. 26 C. helena ; 29 T. 



ceylonensis ; 30 T. stolatus ; 31 T. asperrimus. 



4. — Head very distinct from neck ; body stout, viperine 



aspect. 32 T. plumbicolor. 



5. — Head slightly distinct from neck ; body rather stout.. 



33 H. schistosus. 



6. — Head short, not distinct from neck ; tail very short, 



20 S. arnenis ; 21 0. templetonii ; 22 0. sublineatus ; 

 43 B. ceylonicus ; 44 B. cseruleus. 



7. — As in a 6 , but tail longer. 23 0. subgriseus. 



8. — Head short, scarcely distinct from neck ; tail moderate. 



18 P. subpunctatus ; 19 A. calamaria ; 41 G. pre- 

 vostiana. 



9. — Head scarcely distinct from neck ; snout much depres- 



sed, with swollen lips, spatulate in the adult. 15 L. 

 aulicus. 



10. — Head long and broad, very distinct ; snout long ; tail 



very short, prehensile. 3 P. molurus. 



g — 45 Naia tripudians. 



As in a, but the neck is extensible, forming a hood 

 when spread out, 



C = 10 ASPIDURA BRACHYHORROS. 



Body cylindrical ; head not distinct from neck, sub- 

 conical ; snout pointed. 



