424 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4TH SER. 
Number. Gastrosteges. Urosteges Postoculars. 
33879 135 58 2-2 
33880 140 58 2-2 
33881 141 26+ 2-2 
33882 142 5 2-2 
33883 135 64 2-2 
33884 143 58 1-1 
33885 140 62 2-2 
33886 141 64 2-2 
33887 148 51 2-2 
33888 143 62 _ 22 
33889 142 59 2-2 
34171 S15 58) 2-2 
The first infralabials of all these specimens are separated 
by the mental. 
The collar in all is from one to three rows of scales behind 
the parietals, is from one to one and a half rows of scales 
in width, and is not edged with darker scales. The lower 
surfaces are suffused with coral-red. 
Although the type of T. wilcoxi was recorded by Cope as 
T. nigriceps, it is probable that the latter has not hitherto been 
taken in Arizona. 
This Arizonan Tantilla is readily distinguished from the 
Californian Tantilla eiseni by its smaller number of gastro- 
steges (135 to 148 as against 167 to 181 in T. eiseni). Tan- 
tilla planiceps from Lower California has only 138 to 140 
gastrosteges, but the white nuchal collar is on the sixth and 
seventh rows of scales behind the parietals. Tantilla wilcoxt 
has a larger number of gastrosteges (148 to 157) and the 
white collar crosses the parietals. 
No. 33885 was colored in life as follows: Upper surface 
of head dark olive, becoming blackish brown posteriorly. 
Labials, lower surface of head and neck to sixth gastrostege, 
tips of all gastrosteges, and two or three rows of lateral scales 
on each side, grayish white. Upper surfaces (except of head) 
unicolor, light yellowish hair-brown or brownish straw. Rest 
of lower surfaces from sixth gastrostege to tip of tail bright 
coral red. 
74.Tantilla wilcoxi Stejneger 
The only example of this species.secured is a fine large 
specimen removed from the stomach of a Diadophis regalis 
