SNAKES OF CEYLON 127 



Identification. — There is no easy guide to the recognition 

 of the genus, but the following syndrome will best indicate 

 it. Costals about one-third as broad as long, and one-third 

 as broad as the ultimate row, in 21 to 27 rows at midbody ; 

 and seven supralabials. 



Habits. — Terrestrial, diurnal. The diet is mainly of a 

 batrachian order. The best known species is oviparous. 



Poison. — All are non-poisonous. 



Lepidosis. — Rostral : Touches six shields, the rostro-nasal 

 sutures longest. 1 nter nasals : Two; the suture between them 

 equal to, or nearly equal to, that between the prefrontals, 

 equal to, or nearly equal to, the internaso -prefrontals. 

 Prefrontals : Two ; the suture between them equal to, or nearly 

 equal to, the prsefronto-frontals. Frontal : Touches six shields ; 

 the fronto -supraocular sutures twice, or nearly twice, the 

 fronto-parietals. Nasals: Two. Loreal : One. Prseoculars : 

 One or two. Postoculars : Three. Temporals : Two ; the 

 lower as long as the supraoculars. Supralabials : Seven or 

 eight ; two touching the eye. Infralabials : Six or seven ; the 

 last three touching the posterior sublinguals. Sublinguals: 

 Two pairs ; the posterior larger. 



Costals. — Longer than broad, rectiform, keeled, with 

 apical facets, apically emarginate. The vertebrals not 

 enlarged. Ultimate row enlarged, the breadth of its scales 

 as long as their length, about three times the breadth of the 

 vertebrals. In 19 to 27 rows at midbody. Swpracaudals : 

 In even rows. Ventrals : 120 to 162 ; rounded. Anal : 

 Divided. Subcaudals : 35 to 60 ; divided. 



Dentition. — Maxillary : Diacranterian ; the praecranterian 

 set isodont. Cranterian ; two ; strongly compressed, and 

 much enlarged. Palatine : Isodont. Pterygoid : Isodont, 

 except last two or three, which are reduced. Mandibular : 

 Isodont, except last two or three, which are reduced. 



Distribution. — Peninsular India, Ceylon, Malay Peninsula, 

 Islands of Malay Archipelago as far east as Java. 



There are three species only, one of which occurs in Penin- 

 sular India and Ceylon, viz., plumbicolor . 



