COLUBRID^. 221 



ground, and are generally of not brilliant coloration ; only a few which frequent grassy 

 plains are of a bright green colour. 



Scales smooth, iii 13-17 series, those on the back equal in size; ventrals not 



angulated ; one loreal ; two nasals ; maxillary teeth equal in length . . Ablabes, p. 223. 



Scales smooth, in 15 series ; one nasal ; maxillary teeth equal in length . . . Cyclophis, p. 229. 



Scales smooth, Ln 13-15 series ; ventrals angulated ; two praeoculars ; maxillary 



teeth equal in length Odontomus, p. 233. 



Scales smooth, in 15 series; ventrals angulated; the three posterior maxillary 



teeth long, trenchant, not grooved Nymphophidium, p. 235. 



Scales smooth, in 17-23 series; ventrals not angulated; two nasals; the pos- 

 terior maxillary tooth longest, either in a continuous series with the others 

 or grooved Coronella, p. 236. 



GROUP OF TRUE COLVBmDES—COLUliRINA. 



These snakes form, as it were, the nucleus of the whole family, or, rather, of the whole 

 suborder of innocuous snakes ; they are typical forms, not characterized by the excessive 

 development of some particular organ, but by the fairness of the proportions of all parts. 

 Yet some of them have a more slender body than others which always live on the ground ; 

 they are land snakes, but swim well when driven into the water, or climb when in search of 

 food. Their scales form never less than fifteen series, generally more. Their teeth are 

 numerous, subequal in size, except in the genus Zamenis. They are of moderate or rather 

 large size. 



Scales smooth or feebly keeled, in 19-27 series; one prseocular; anal bifid; 



maxillary teeth equal in length Coluber, p. 237. 



Scales keeled ; ventrals 200 or more in number ; anal bifid ; one loreal ; two 



prseoculars ; maxillaiy teeth equal in length Elaphis, p. 240. 



Scales keeled, in 19-23 series ; ventrals more than 200 in number ; anal entire 



(except in C. hodgsonii) ; one praeocular; maxillary teeth equal in length . Compsosoma, p. 243. 



Scales keeled or with a pair of apical grooves, in 25-27 series ; ventrals more 

 than 200 in number ; anal entire ; one prseocular ; maxillary teeth sub- 

 equal in size Cynophis, p. 246. 



Scales smooth or feebly keeled, in 15-17 series ; loreals two or three .... Ptyas, p. 248. 



Scales smooth, in 17 series, those of the vertebral series hexagonal .... Xenelaphis, j). 250. 



The posterior maxiUary tooth is lengtlieued, and separated from the others by a 

 short interspace ; ventral shields 200 or more in number, rounded or very 

 indistinctly angulated Zamenis, p. 252. 



GROUP OF BUSH COLUBRIDES— -Di?r^i)/iY./l. 



The form of these snakes is elongate and somewhat compressed, indicating their climbing 

 propensities; they have the body not so excessively slender as the true Tree Snakes, to 

 which they lead off. They are much more numerous in the New World than in the Old. 



