30 CALIFORNIA ACADEMY OF SCIENCES [Paoc. 4th Ser. 



Type. — Cal. Acad. Sci. No. 45888, collected by Joseph R. 

 Slevin at Agua Caliente, Cape Region of Lower California, 

 July 26, 1919. 



Distribution. — The southern portion of Lower California, 

 Mexico. 



Description of type. — Large. Head broad, fiat-topped ; ros- 

 tral higher than wide, in contact with anterior nasal. Two 

 nasals ; two preoculars ; three postoculars ; two loreals. Supra- 

 ocular large, not raised into a horn-like process, separated from 

 its fellow by about six or seven irregular rows of scales. Six- 

 teen and seventeen superior and nineteen inferior labials, the 

 first pair of the latter divided horizontally as in C. exsul. A 

 single pair of genials. About five rows of scales between 

 supralabials and eye. Scales in twenty-seven rows, keeled ex- 

 cept in one or two rows on each side. Gastrosteges 186; 

 urosteges 26. 



The general color is yellowish-brown, or brownish-yellow, 

 with a series of large, darker brown blotches along the back. 

 These blotches are well defined, are usually enclosed in con- 

 tinuous light borders laterally as well as dorsally, and show 

 little of the punctulate or pepper-and-salt style of coloration so 

 characteristic of C. atrox. The sides are clouded or blotched 

 with brown, more or less indefinitely outlined with light yellow 

 or white. The head is somewhat mottled above. A yellow or 

 white stripe runs across the side of the face from the preocular 

 plates to the mouth. The scales behind and above this light 

 stripe are darker than the ground color and are set off pos- 

 teriorly by a light streak which runs down and back from the 

 corner of the mouth. The tail is grayish with about four to six 

 black cross-bands. The lower surfaces are yellowish-white. 



Length to anus 1070 mm. 



Length of tail to base of rattle 90 " 



