I06 UNIVERSITY OF COLORADO STUDIES 



Specimens of this species tend to retain the cross bands of the 

 young color pattern even as adults. Range, western Texas to Cali- 

 fornia, south well into Mexico and north into Colorado and Utah. 



Genus TANTILLA Baird and Girard 



Tantilla Baird and Girard, Cat. N. Am. Reptiles, Pt. I, p. 131, 1853. 

 Homalocranium Dumeril et Bibron, Mem. Acad. Sci., XXIII, 490, 1853. 



Anal plate divided; scales smooth and polished, in 15 rows; pos- 

 terior maxillary teeth grooved and separated from the others by an 

 interspace; size small; color reddish or brownish. 



These snakes are found in North, Central and South America and 

 the West Indies. 



Tantilla nigriceps Kennicott 



Texas Black-Headed Snake {Figure 34) 



Tantilla nigriceps Kennicott, Proc. Acad. Nat. Sci. Phila., p. 328, i860. 



Size small, not exceeding twenty inches. 



Dorsal scales smooth and polished, in 15 rows; upper labials, 7; 

 inferior labials, 6; ventrals, about 155, 



Uniform yellowish, red brown or drab color above, shading to 

 white, pale yellow or pink below; top of the head blackish brown to 

 almost black, the dark color extending to the level of the eyes on each 

 side and back of the head for about three rows of scales; posterior 

 margin of the colored area V-shaped. Rostral region lighter. 



These seem to be the first records for this little snake in Colorado, 

 and Yuma is the most northern point from which it has been taken. 

 Cope' does not list it north of Wichita River, Tex., although Branson* 

 finds it as a rare snake in southern Kansas. 



It is a very retiring snake, and burrows for its food. This consists 

 of insect larvae and earthworms. 



This species ranges through Texas, where it is quite abundant, 

 north to Colorado and Kansas and west to Arizona. 



Colorado specimens. — University Museum: La Junta, July, 1905 (220 mm.), 

 G. S. Dodds, No. 256; Colorado State Historical and Natural History Museum: 

 Yuma, near Dry Willow Creek, July 7, 1905 (340 mm.), H. G. Smith. 



' Cope, Rept. U.S.N.M., p. 1114, i8g8. ' Branson, Kans. Univ. Sci. Bull., Vol. II, p. 415. 1902. 



