24 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



Walla Walla County, Washington, may belong here rather 

 than with P. catenifer deserticola, but their final disposition 

 must await additional material. They have twenty-nine and 

 thirty-one scale-rows and one or two preoculars (50% each), 

 and gastrosteges from 23 1 to 244. 



Pituophis catenifer rutilus, new subspecies 



Arizona Gopher-Snake 



(Plate 2, fig. 2) 



Diagnosis. — Gastrosteges numerous, average more than 

 225 ; urosteges average 57 to 63 ; scale-rows most frequently 

 33 ; preocular normally single ; supralabials usually eight ; dor- 

 sal blotches very few, average on body 46, on tail 12.5 ; colora- 

 tion often somewhat reddish posteriorly. 



Type. — Cal. Acad. Sci. No. 33869, adult female, collected 

 by J. R. Slevin at Tucson, Pima Co., Arizona, April 11, 1912. 



Description. — Head somewhat flat-topped, with snout pro- 

 jecting and rather narrow. Temporal regions not swollen. 

 Rostral plate very large, prominent, not very narrow, often re- 

 curved between internasals on top of snout ; bounded behind by 

 internasal, anterior nasal, and first labial plates. Plates on top 

 of head are a pair of internasals, a variable number of pre- 

 frontals (normally four), a frontal, supraocular of each side, 

 and a pair of parietals. Anterior and posterior nasals usually 

 distinct. Loreal usually elongate. Preocular usually one, oc- 

 casionally two. Postoculars usually three, often four, some- 

 times five. Supralabials usually eight, often nine, rarely 10. 

 Infralabials usually 12, often 13, sometimes 11 or 14. Tem- 

 porals of first row varying from two to five, usually four. 

 Genials in two pairs, anterior larger. Scales on body in 29 to 

 35 rows, usually 33, keeled except in a varying number of rows 

 on each side. Anal plate not divided. Gastrosteges varying in 

 number from 222 to 258, males having from 222 to 237, fe- 

 males from 227 to 258. Urosteges in two series of from 52 

 to 68, males having from 57 to 68, females from 52 to 60. 



The ground color is pale yellow or grayish-yellow, some- 

 times more or less obscured by the spreading of the blotches 



