880 



REPORT OF NATIONAL MUSEUM, 1898. 



a longitudinal band of the same color, which deepens posteriorly, and 

 unites with its fellow at intervals of three or four scales by a gradual 

 widening upon its dorsal border. Thus a scalariform series of dorsal 

 blotches is formed, whose transverse diameter increases regularly pos- 

 teriorly, and whose intervals diminish, being anteriorly four scales, 

 upon the tail one and a half. The connecting band remains unbroken 

 upon the anterior fourth of the body only. Separated from this by an 

 interval of one half or a whole scale, another longitudinal and very 

 narrow band arises on the neck. It is much more distinct opposite the 



Fig. 209. 



PiTYOPHIS VERTBBRALIS BlAINVILLE. 

 = 1. 



La Paz, Lower California. 



Cat. No. 12644, U.S.N.M. 



intervals between the dorsal blotches, and upon the disappearance of 

 the line connecting the latter j)artially assumes its position, and breaks 

 up into an alternating series of very elongated spots. The dorsal inter- 

 vals are thus widened to a breadth of seven and two halves scales. 

 There also begins upon the neck a second lateral series of spots, 

 which occupy a length of live scales on the fourth, fifth, and sixth rows. 

 Their length decreases to three scales opposite the anus, where they 

 unite with the superior lateral series. Every second pair of gastro- 

 steges is tipped with sanguineous. All the markings of this serpent 

 are sanguineous anteriorly, but deeper posteriorly, passing through 



