882 13. COLUBRID 
brightest just in front of the anus. One specimen had the 
entire lower surface coral red, becoming grayish or yellow- 
ish white in alcohol. 
Length to anus__-.____ 161 162 167 187 188 193 
Length of tail.____ 58 58 Sve 64 63 67 
Distribution.—This species is known only from Lower 
California, Mexico, where it has been collected in the Cape 
Region near San Jose del Cabo and in the Sierra de la La- 
guna. It also has been taken north of the Cape Region near 
Santa Rosalia and San Ignacio. 
Remarks.—Tanitilla planiceps resembles T. nigriceps in 
the number of its gastrosteges, but its nuchal collar is placed 
farther from the parietal plates. 
Habits—Mocquard states: “Cet ophidien vit dans le sol, 
ott on le rencontre surtout en pratiquant des terrassements.” 
203. Tantilla wilcoxi Stejneger 
ARIZONA TANTILLA 
Tantilla nigriceps Cope, Report U. S. Nat. Mus. for 1898, 1900, p. 1113 
(part). 
Tantilla coronata VAN DeNBURGH, Proc. Cal. Acad. Sci., Ser. 2, Vol. 6, 
1896, p. 346. 
Tantilla wilcoxi STEJNEGER, Proc. U. S. Nat. Mus., Vol. XXV, 1902, 
p- 156 (type locality, Fort Huachuca, Arizona); Van DenburGH 
& Sievin, Proc. Cal. Acad. Sci., Ser. 4, Vol. 3, 1913, p. 424; STEJ- 
NEGER & Barsour, Check List N. Amer. Amph. Rept., 1917, 
p- 107. 
Description —Head rounded in outline, very flat above, 
rather broad across temporal region, but little distinct from 
neck. Eye moderate. Rostral rather large, broader than 
high, and bounded behind by internasal, anterior nasal, and 
first labial plates. Plates on top of head are a pair of small 
