156 PROCEEDTNGS OF THE NATIONAL MUSEUM. vol. xxv. 



tion b}' larger spots on the sides under the lateral lin(\ ])v a horseshoe- 

 shaped black mark on the sutures of the seventh supralal)ial and l)y the 

 dorsal line not reaching- the parietals, but there seem to he too many 

 exceptions to make it expedient to recognize a subspecies based on 

 these characters. Thus among the Huachuca specimens No. 22205 

 has the spots below the lateral line as heavy as the type of cyrtojMis^ 

 and the horseshoe mark is clearly indicated. Then, again, in the 

 Coahuila specimens without this mark and the spots the dorsal line 

 does not reach the parietals, while a specimen from San Antonio, 

 Texas (No. 22387), has heavy spots, but no horseshoe, and the dorsal 

 line reaches the parietals. With the present material, therefore, lam 

 unable to recognize any subspecies of T. cy7'topsis. 



TANTILLA WILCOXI, new species. 



DIfujnosis. — Eye more than half as long as the snout; frontal less 

 than twice as broad as the posterior border of the supraocular; seven 

 upper labials; twopostoculars; frontal six-sided, anterior angle obtuse, 

 posterior acute; ventrals about 150; two pairs of chin-shields, anterior 

 pair longer than posterior; rostral much broader than deep; frontal 

 once and a half as long as broad, longer than interparietal suture; hrst 

 lower la))ials not in contact behind the mental; posterior nasal and 

 preocular large, broadly in contact; a white coUar two scales wide 

 just behind the parietals and taking in their extreme posterior angle, 

 followed b}^ a narrow dark band only one and a half scales wide. 



Ilahitat. — Southern Arizona. 



Ty2)e.—^o. 19674, U.S.N.M.; Fort Huachuca, Arizona; Dr. T. E. 

 Wilcox, coll. 



Description of the type. — Head broad, especially across the temples, 

 much wider than neck; eye large, more than half as long as the 

 snout, and nearly twice as large as its distance from the conuuissure; 

 rostral much wider than high, the portion visible from above equals 

 the internasal suture; internasals short, less than half as large as the 

 prefrontals, the lower border of which is wedged in between posterior 

 nasal and preocular. but not in contact with supralabials; frontal six- 

 sided, the anterior angle obtuse, the posterior acute, the lateral sides 

 converging backward, its width about two-thirds its length and less 

 than twice the width of the supraoculars, its length equaling the 

 interparietal suture, though slightly shorter than the parietals; supra- 

 oculars, rather larger, their width more than half that of the frontal; 

 parietals as long as their distance from tip of snout; nasals and pre- 

 ocular of about equal size, the latter broadly in contact with posterior 

 nasal; one prebcular; two postoculars; temporals 1+1, long and nar- 

 row; supralabials 7, seventh very high, third low, fourth nearly twice 

 as wide as third, both entering eye; infralabials 7, four in contact with 

 anterior chin-shields, first pair not in contact with each other behind men- 

 tal; anterior chin-shields very long, nuuli longer than second; 15 rows 



