13. COLUBRIDM 



Description. — Head wide, with flattened top and broad, 

 rounded snout. Rostral plate large, high, hollowed below, 

 and bounded behind by internasal, nasal and first labial 

 plates. Plates on top of head, a pair of internasals, a pair 

 of prefrontals, a frontal broad in front but pointed behind, 

 a long supraocular on each side, and a pair of large parietals. 

 Anterior and posterior nasal plates frequently united above 

 or both above and below, nostril. Loreal small and nearly 

 square. Normally one preocular, but two very rarely 

 present. Postoculars two, rarely one. Temporals one 

 followed by two, rarely l + I. Seven (very rarely six) 

 superior and seven inferior labials, sixth upper and fourth 

 lower largest, third and fourth upper bordering eye, first 

 pair of lower meeting on median line behind the small tri- 

 angular mental. Genials in two pairs, anterior much larger 

 than posterior. Scales on body smooth, in 15 rows. Anal 

 plate divided. Gastrosteges varying in number from 147 

 to 186. Urosteges in two series of from 27 to 57. Tail 

 short, conical, ending in a sharply pointed plate. 



The color above is grayish or yellowish brown, usually 

 very finely punctulated or reticulated with slate or black, 

 with or without a light yellowish or brownish line along 

 each side. The scales below these lines are sometimes spot- 

 ted with black. In very young specimens a continuous black 

 line along each side takes the place of these spots, while a 

 similar line runs along the middle of the back. The sides of 

 the head show these lateral black lines more or less distinctly. 

 The tail is colored like the back, except that its upper surface 

 is sometimes suffused with red. The lower surfaces are gray- 

 ish or yellowish white, transversely barred with black on the 

 anterior half of each gastrostege and (often) urostege. 



