COLUBER ^. 



119 



2. Scales in odd numbers, forming 



straight longitudinal series. 



a, VentralsandsLibcaudalsrounded 



or more or less distinctly 

 angulate laterally. 



Scales in 15 to 23 rows, vertebrals not en- 

 larged ; maxillary teeth increasing in 

 size posteriorly Zamenis, p. 136. 



Scales ill 17 rows, vertebrals slightly en- 

 larged ; maxillary teeth increasing in size 

 posteriorly Xenelaphis, p. 139. 



Scales in 19 to 27 rows; teeth equal Coluber, p. 139. 



b. Ventrals and subcaudals Avith a 



suture-like lateral keel and a 

 notch on each side, corre- 

 sponding to the keel ; scales in 

 19 rows GoNYOPHis, p. 144. 



3. Scales in 13 or 15 rows, oblique ; 



ventrals and subcaudals with a 

 suture-like lateral keel and a 

 notch on each side corresponding 

 to the keel. 



Teeth increasing in size posteriorly ; verte- 

 bral scales enlarged Dendrophis, p. 145. 



Teeth decreasing in size posteriorly ; verte- 

 bral scales not or but slightly enlarged. . Dendrelaphis, p. 146. 



Fig. 40, — Scaling of body of Dendrophis pictiis, showing the enlarged vertebral 

 scales (8), the apical pit* on the oblique dorsal scales, and the lateral 

 keel along the ventral sliiekls {v). 



* The apical pit is a minute impression near the extremity of the scale > 

 these pits may be disposed in pairs. The character derived from the presence 

 or absence of the apical pits appears to me of about the same systematic import- 

 ance as the presence or absence of a keel on the dorsal scales, or the division 

 or non-division of the subcaudal shields. In some cases it may aid in defining 

 a natural gemis, in others it breaks down as a generic character. 



