166 BULLETIN 114, UNITED STATES NATIONAL MUSEUM. 



Head somewhat distinct from the neck; body moderately stout, 

 cylindrical; tail tapering, 0.115 to 0.156 of the total length (males, 

 0.124 to 0.156, average about 0.141; females, 0.115 to 0.148, average 

 about 0.134). The largest specimen from a typical portion of the 

 range (Wheeler County, Texas) is 713 mm. in length. Some exam- 

 ples from central Kansas are larger than this. 



The pattern (fig. 72) on body and tail is composed of 25 to 40 

 whitish annuli from one to three scales wide dorsally and from two 

 to five in width on the first row of scales. Between these rings are 

 pairs of black annuli separated by red. The black and white rings 

 are continuous across the belly, but the space there between the 

 black rings and opposite the dorsal red areas is usually filled with 

 black. The latter color tends to encroach upon the red, and, on 

 the middorsal lines the black rings of adjacent pairs are often con- 

 fluent. The whitish rings are usually mottled on the sides with 

 darker; the belly is generally crossed by approximately equal bands 

 of black and white, but the white areas may be blotched with darker, 

 the black may be partly broken up, and rarely there is little or no 

 black below. 



The head is generally a uniform black on the posterior half, and 

 this black may extend forward over the snout. The latter is, how- 

 ever, usually lightened, at least on the sides. The labials show 

 varying proportions of dark and light, corresponding with the extent 

 of black on the head. 



The actual colors of the whitish annuli, according to Ellis (1913, 91), 

 are light gray to bright yellow, while the red varies from slate brown, 

 through brick red, to scarlet. A specimen from Blue !River, Nebraska, 

 bears the note: '' Original color: Deep orange, lemon yellow, and 

 black." The red and yellow fade to white in alcohol. 



The dentition, as revealed by the examination of a few specimens, 

 is as follows: Maxillary teeth, 12 to 14, most often 13, the last 2 

 slightly larger; mandibulars, 12 to 15, the third and fourth largest, a 

 little greater space between the fourth and fifth; palatines, 10 or 11, 

 oftener 10; pterygoids, 16 to 20. 



This form may nearly always be immediately recognized by its 

 black head with snout mottled with red and black, its conspicuous 

 black rings which encroach on the red dorsally and are separated by 

 not more than 40 nor less than 25 whitish annuli on body and tail. 

 Specimens examined from west of the Rockies, where the color pat- 

 tern is confusingly similar to that of pyrrliomelaena and multidncta^ 

 have less than 200 ventrals, while the latter forms have several to 

 many more. Its distinction from amaura and from syspila is given 

 under these respective forms. 



Habitat and habits. — ^Apparently nothing has been recorded on the 

 natural history of this form. 



