806 13. COLUBRID#® 
Bafios, Gadwall, Snelling), San Joaquin (Banta), Contra 
Costa (Walnut Creek), Alameda (Berkeley), Santa Clara 
(Palo Alto, Castro, San Jose, Uvas Creek), Santa Cruz 
(Glenwood), Monterey (Pacific Grove, Seaside, Carmel, 
Mt. Mars), San Luis Obispo (Edna), San Bernardino 
(Ontario, Colton), Los Angeles (Los Angeles, Bixby), and 
Riverside (Riverside) counties. 
The following localities are represented each by one 
specimen. The material being so limited one cannot state 
positively to which subspecies of sirtalis these specimens 
should be referred, but it is probable that they belong here. 
Willow Lake, Tehama County, Susanville, Lassen County, 
and Fallen Leaf Lake, E] Dorado County, California, and 
Nixon, Washoe County, Nevada. 
It probably will prove to be impossible to draw any 
very definite limits to the areas occupied by this form and 
by 7. sirtalis concinnus. This must be so, for one gradually 
changes into the other. The area of intergradation is a 
broad one, individual variation is great, and opinions may 
easily differ as to geographical limits. Our own views are 
expressed in the lists of localities given under each subspecies. 
These indicate that to T. sirtalis concinnus are referred 
snakes from Del Norte, Siskiyou, Shasta, Humboldt, Men- 
docino, Sonoma, Napa, and Marin counties, while those from 
elsewhere in California are regarded as T. sirtalis infernalis. 
Remarks.—This subspecies differs from both 7’. sirtalis 
parietalis and T. sirtalis concinnus in having a greater num- 
ber of gastrosteges and urosteges. This is clearly shown 
in the following table of average counts: 
