CROCODILIANS, LIZARDS, AND SNAKES. 



931 



RHINOCHILUS LECONTEI Baird and Girard. 



RliinocliUus lecontei Baird and (jIRAkd, Cat. N. Ainer. K*'i>t., Pt. 1, Serp., 1853, 

 p. 120; Kept. U. S. Expl. K. R., X, Pt. 3, 1859, pi. xxxiu, fig. 90.— Baikd, U. S. 

 Mex. Boundary Surv., II, Rept., 1859, p. 21, pi. xx.— Jax, Arch. Zool. Anat. 

 Phys., II, 1863, p. 217; Icon. Gen. Ophid., 1876, Pt. 48, pi. in, fig. 1.— Cope, 

 Proc. Acad. Nat. Sci. Phila., 1866, p. 304; Check-list N. Amer. Batr. Rept., 

 1875, p. 36; Pvoc. U. S. Nat. Mus., XIV, 1892, p. 606.— Gakman, N. Amer. 

 Rept., 1883, p. 73.— BocouRT, Miss. Sci. Mex., Rept., 1886, p. 602, pi. xl, 

 fig. 7. — GIJNTHKK, Biol. Centr.-Amer., Rept., 1893, p. 100.— Boulexger, Cat. 

 Snakes Brit. Mus., II, 1894, p. 212. 



Head distiuct from the body ; broad behind, nearly flat above. Ver- 

 tical plate hexagonal, elongated, largest anteriorly, the lateral edges 

 tapering, and constituting the longest sides of the figure. Supercili- 

 aries quite large. Occipitals subangular, proportionally small. Pre- 

 fontals large compared to the postfrontals. Rostral prominent for- 

 ward, rouuded beneath, tapering upward. Eyes large, over the junc- 



Fig. 236. 



RHINOCHILUS LECONTEI BaiRD AND (xniAid). 



= 1. 



Sau Angelo, Western Texas. 



Collection of E.D.Cope. 



tion of the fourth and fifth upper labials, about opposite the middle of 

 the commissure. Postorbitals two, lower in notch between the lifth 

 and sixth labials, although resting more on tlie latter. Anteorbital 

 large, resting on the fourth labial, the fourth and fifth labials oonstitut- 

 iug equally the inferior part of the orbit. Loreal elongated, horizontal, 

 trapezoidal; well developed. Nasals apparently double, perhaps a sin- 

 gle one verj' much excavated. Two temporal shields between the occip- 

 itals and labials. Labials eight above, seventh largest; eight below, 

 tiftli largest. Dorsal rows of scales twenty-three, all perfectly smooth ; 

 scales rhomboidal, nearly equal, but rather narrow above. Abdominal 

 scutelUe two hundred and six; posterior one entire. Subcaudal scu- 

 telhc forty, all entire. 



The body is crossed by about thirty-three quadrate black blotches, 

 the twenty- seventh opposite the anus. These are nearly of the same 

 length, and of the same distance apart throughout, four scales long, 

 and extending between the second external rows, where their sides are 

 rather rounded or angulated. The black is very deep and continuous 



