84 SNAKES OF CEYLON. 



The mandible in this genus is also peculiar, the posterior 

 two-thirds of the dentary bone being loose, instead of forming 

 a synarthrosis with the articular bone. This is a condition 

 I have not seen in any other snake in the family Colubridas, 

 and resembles that seen in only one other family, viz., 

 Xenopeltidae. 



Distribution. — Madagascar and Comoro Islands, South 

 Eastern Asia, Central America. There are ten species, of 

 which four are Indian, and of these one only occurs in Ceylon, 

 viz., subpunctatus. 



Polyodontophis subpunctatus Dumeril and Bibron. 



. Jerdon's Polyodont. 



(Latin ''sub" beneath, and " punctatus " literally pricked ; 

 refers to the small spots on the belly.) 



Synonymy. — Galamaria sagittaria, Oligodon subpunctatus, 

 0. spinsepunctatus , Enicognathus melanocephalus, E. humberti, 

 Ablabes humberti, Ehadinea melanocephala. 



History. — First referred to, and figured by Seba in 1734 

 (Vol. I., Plate XI.). Not referred to again until 1853, when 

 Jerdon described it under the name Calamaria sagittaria. 

 (Journal of the Asiatic Society of Bengal, Vol. XXII., 

 p. 528), confusing it with Cantor's species of that name. 

 Re-christened by Dumeril and Bibron in 1854, whose name 

 now stands. 



General Characters. — A small species hardly 18 inches in 

 length. Head about as broad as the body. Snout moderate 

 in length, with a slightly-indicated, and obtusely-rounded 

 canthus. Eye moderate, with round pupil. Nostril, small. 

 Neck scarcely apparent. Body moderate in length, cylindrical, 

 and of even calibre throughout. Belly rounded. Tail 

 rather short, being about one -fourth the total length. 



Identification. — It is the only Ceylon snake with the costals 

 in 17 rows in the whole body length, with a divided anal 

 shield, and divided subcaudals. The ten supralabials, with 

 the last deepest and longest, is also very distinctive. 



Colouration. — Dorsally grayish or fawn-coloured. Each 

 scale is powdered with dark brown. Sometimes dark basal 



