1901.] NATURAL SCIENCES OF riTILADELPHIA. 93 



Key to the Species in United States. 



a. — Upper labials 7: 



«\ — A yellow or white collar on nape: 



A black band behind collar; ventrals less than 158, 



1. 2\ coronata. 

 Black dots behind collar; ventrals more than 167, 



2. T. eiseni. 



h\ — No collar on nape; head black, . . 3. T. nigriceps. 



b. — Upper labials 6, 4. T. gracilis. 



Tantilla coronata B. and G. 



I. c., 131 ; Cope, I. c, 598, and Rep. Nat. Mus., 1114 ; no7nalocranium 

 coronatum Boul., Ill, 218. 



Size small and slender; head not distinct; head plates normal; 

 no loreal; posterior nasal in contact with preocular; oculars 1-2; 

 temporals 1-1 (2); upper labials 7; scales in 15 rows; ventrals 

 138-158; subcaudals 35-58. Length 220 mm. (tail 35). 



Eeddish brown above; belly whitish; top of head dark brown 

 with a yellow cross-band behind the parietals, bordered behind by 

 a black one two scales wide. 



Hab. — Gulf States; Georgia to Mississippi. 



Tantilla eiseni Stejneger. 



Proc. U. S. Nat. Mus., 1895, 117. 



Size rather larger; post-nasal almost separated from the pre- 

 ocular by the prefrontal; ventrals 167-181; subcaudals 58-65. 

 Length 365 mm. (tail 82). Much resembling T. coronata, but 

 w^ith a more slender body, a longer tail and a greater number of 

 ventrals and subcaudals. The only specimens known have been 

 more than twenty years in spirits, but from Mr. Stejneger's descrip- 

 tion the color must have been like coronata, but the collar was 

 bordered behind by black dots in place of a band. 



Hab. — Seven specimens known, all from Fresno, California. 



Tantilla nigriceps Kennicott. 



Troc. Acad. Phila., 1860, 328; Cope, I. c, 598, aud Eep. Nat. Mus., 

 1113; H. pkmiceps (part) Boul., I. c, III, 226. 



Size small; post-nasal usually in contact with preocular; oculars 

 1-1 (2); temporals 1-1; upper labials 7; scales in 15 rows; 

 ventrals 121-168; subcaudals 42-66. Length 275 mm. (tail one- 

 fifth). 



Yellowish biown above; white underneath; top of head blackish 

 brown ; no collar. 



