SNAKES OF THE GENUS PITUOPHIS 



149 



average 66.6 in males, 65.4 in females; tail spots average 22.1 in males, 

 19.9 in females. 



Two specimens, one from Fort Tejon, Kern County, Calif., and the 

 other from Puget Sound, Wash., vary from the normal in the presence 

 of only two prefrontals instead of four. 



A specimen of catenifer with two heads, from Los Gatos, Santa 



10 19 PA 15 82 



52 



14 15 



94 

 92 

 90 

 8" 

 86 

 84 

 82 

 80 

 78 

 76 

 74 

 72 

 70 

 68 

 66 

 64 

 62 

 60 

 58 

 56 

 54 

 52 

 50 

 48 

 46 

 44 



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Region 1 

 No. 



2 3 4 5 6 7 8 9 10 11 12 13 

 FiGUEE 70.— Geographic variation in number of dorsal spots on the body in Pituophis catenifer catenifer. 



Clara County, Calif., is described by Wright (1878, p. 97) and later 

 by Johnson (1901, p. 526). Wright says: 



This two-headed one is 22 inches long, of uncertain age, but perhaps only a few 

 months old, since full-grown ones attain a length of from six to seven feet. Its 

 ground color is a dingy, yellowish-white, with a dorsal row of chestnut brown spots, 

 nearly square and 75 in number, from the point where the two necks separate, 

 extending its full length. On each side are two lateral rows of smaller spots of 



