Vol. X] VAN DENBURGH— VARIATION IN GOPHER-SNAKES 27 



Habits. — Ruthven states that a large specimen, secured near 

 Tucson about sun-down on August 22, had recently swallowed 

 an adult ground squirrel. These snakes live both on the desert 

 plains near sea level and in mountain canons to an altitude of 

 at least 5,300 feet. 



Pituophis vertebralis (Blainville) 

 San Lucan Gopher-Snake 



Diagnosis. — Gastrosteges average moi-e than 240; urosteges 

 average 62 ; scale rows most frequently 35 ; preoculars usually 

 two; supralabials usually nine or 10; dorsal blotches very few, 

 average on body 44, on tail 1 1 ; much red in coloration. 



Type locality. — "California." 



Distribution. — The southern half of the peninsula of Lx)wer 

 California, Mexico. 



Variation. — Fourteen specimens show the following varia- 

 tions: The loreal is 1-1 in all counted (six). The preoculars 

 are 2-2 in thirteen, or 93% ; 1-1 in one, or 7%. The postocu- 

 lars are 3-3 in fourteen, or 100%. The temporals in five speci- 

 mens are 4-4 in three, or 60% ; 3—4 in on«, or 20%, and 4-5 in 

 one, or 20%. The supralabials are 9-9 in seven, or 50% ; 9-10 

 in five, or 36% ; 8-9 in one, or 7% ; and 8-10 in one, or 7%. 

 The infralabials are 12-12 in seven, or 50% ; 13-13 in three, or 

 22% ; 13-14 in two, or 14% ; 12-13 in one, or 7% ; and 14-16 

 in one, or 7%. The scale-rows are 35 in seven, or 54% ; 33 in 

 four, or 31% ; 34 in one, or 7% ; and 31 in one, or 7% ; the 

 average is 34 rows. The gastrosteges in fifteen specimens vary 

 from 233 to 257, the average being 244; two males average 

 242, four females average 250. The urosteges in fourteen 

 specimens vary from 57 to 67 ; the average being 62 ; two males 

 average 63, and three females, 60. 



The dark blotches between head and anus in six specimens 

 vary from 39 to 48, the average being 44. On the tail in six 

 specimens they vary from 10 to 12, and average 11. 



Counts of the dorsal blotches on the body and tail in six 

 specimensare45, 10;39, 11;48, 11; 43, 10; 44, 11; and 45, 12. 



