414 



KANSAS UNIVERSITY SCIENCE BULLETIN. 



Fig. 32. 

 Tantilla gracilis B. and G. 



Vertical plate subhexagoiial, much shorter than in T. nigri- 

 ceps. Postfrontals separated from the second upper labial by 

 the postnasal. Nostril in the posterior part of the prenasal. 

 Eyes very small, circular. Superciliaries proportionally 

 smaller and narrower than in T. nigriceps. One antorbital 

 and one postorbital, both angular. Mouth deeply cleft. Up- 

 per labials six; fifth and sixth equal, larger than the rest; 

 third and fourth beneath the eye, entering slightly into the 

 orbit anteriorly and posteriorly. Temporal shields two, nar- 

 row and elongated. Body slender and subcylindrical, covered 

 above with subrhomboidal or elliptical and smooth scales, in 

 fifteen rows. Outer row but slightly larger than the three suc- 

 ceeding rows. Tail very slender. Gastrosteges in type speci- 

 men 130, urosteges 45. 



Cope (10. 113) says of the specimen described by Hallowell 

 in 1856 as a variety of gracilis and given by himself as a new 

 species, T. haUoivellii, in 1860: '*'! think the supposed species 

 represents only an extreme individual variation." The speci- 

 men described by Hallowell was collected in Kansas by Doctor 

 Hammond. 



One specimen of Tantilla gracilis from Wilson county is in 

 the museum at Washburn College. 



Tantilla nigriceps Kennicott. 



Black-headed Tantilla. 

 Tantilla nigriceps Kennicott, Proc. Acad. Nat. Sci. Phila., 1860, p. 328. 

 Scolecophls fumiceps Cope, Proc. Acad. Nat. Sci. Phila., 1860, p. 371. 

 Hamalocranium praeoculum Bocourt, Miss. Sci. Mex. Rept., 1883, p. 582. 



Fifteen rows of scales, all smooth. Internasals much wider 

 than long. Prefrontals pentagonal, wider than long. Frontal 

 hexagonal, margins slightly convex. Nostril in posterior edge 

 of anterior nasal ; postnasal pentagonal, in contact with pre- 

 ocular. Two postoculars and one preocular. Rostral visible 



