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



Where individual variation is so great in races which inte- 

 grade and are so closely related, it probably is impossible to 

 make a "key" which will properly refer all specimens. How- 

 ever, it is believed that the following synopsis will serve this 

 purpose for most individual specimens, and perhaps for all 

 series of specimens from one locality. 



Synopsis of Species and Subspecies 



a. Coloration on anterior half of body not largely red. 



b. The number of gastrosteges less the number of dorsal blotches on 

 body and tail rarely exceeds 151. 

 c. Gastrosteges fewer (200 to 230), average fewer than 225; 

 urosteges fewer (51 to 80), average in males 70, females 63; 

 scale-rows usually (70 to 75%) not more than 31. 

 d. Dorsal blotches more numerous on body (56 to 93, average 

 70) and tail (14 to 30, average 21.4). 



P. c. catenifer. — p. 13 



dd. Dorsal blotches fewer on body (48 to 70, average 57.6) and 

 tail (13 to 19, average 15). 



P. c. heermanni. — p. 16 



CO. Gastrosteges more numerous (217 to 243), average more than 

 225; urosteges more numerous (62 to 85), average in males 76, 

 females 70; scale-rows usually (63%) more than 31. 



Dorsal blotches numerous on body (54 to 89, average 74) 

 and tail (14 to 29, average 22.8). 



P. c. annectens. — p. 17 



bb. The number of gastrosteges less the number of dorsal blotches on 

 body and tail usually exceeds 151 ; gastrosteges more than 220. 



e. The sum of the number of scale-rows and of preoculars 

 on both sides of head rarely exceeds 2)Z\ usually one 

 preocular. 



P. c. stejnegeri. — p. 21 



ee. The sum of the number of scale-rows and of pre- 

 oculars on both sides of head usually exceeds Z2>. 

 f. The sum of the number of caudal blotches and 

 preoculars of both sides of head usually exceeds 

 16; usually two preoculars; posterior dorsal 

 blotches not distinctly reddish. 



P. c. dcscrticola. — p. 19 



ff. The sum of the number of caudal blotches and pre- 

 oculars of both sides of head rarely exceeds 16; 

 usually one preocular; posterior dorsal blotches 

 often distinctly reddish or red-brown. 



P. c. rutilus. — p. 24 



aa. Coloration on anterior half of body largely red. Gastrosteges 233 to 

 257; scales usually in 35 or 2i2> rows; dorsal blotches few (average 44 

 on body, 11 on tail) ; supralabials usually nine or more. 



P. vertebralis. — p. 27 



