COLORATION 31 



is continued on the temple and along the side of the 

 body; the fourth follows the lower lip, and extends 

 along each side of the belly. Bearing this in mind, 

 we find that the variety of C. leopardinus named 

 schwoederi, with a vertebral series of paired spots, is 

 to be regarded as the most primitive, from which we 

 can derive, on the one hand, the true leopardinus by 

 imagining a transverse fusion of the spots of series D 

 into a single row, some of the spots often actually 

 revealing, in their biscuit shape, their dual origin ; 

 whilst, on the other hand, confluence of the paired 

 spots of the same series into two longitudinal stripes 

 produces the variety named quadrilineatus (see 

 Plate VII.). In this particular instance, the paired 

 series D has fused into a single streak on the head, 

 and the series L appears to have departed from its 

 primitive course to extend on the upper surface of 

 the head, both in front of and behind the eye. 



Many snakes show an interocular band extending 

 from lip to lip, through the eyes, across the inter- 

 orbital region. In others the lateral stripe L may 

 bifurcate in front of the eye, an upper branch 

 extending across the snout, through transverse 

 fusion of series D and DL, and it may also bifurcate 

 in like manner on the temporal region, fusing with 

 the corresponding marking on the other side to form 

 a W-shaped figure. The pattern of markings on the 

 upper surface of the head is, however, often very 

 complicated, and hence difficult of explanation. 



