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



Remarks. — No. 35248 has the anal divided. The posterior 

 genials are either equal to or longer than the anterior. 



Oak Creek is a mountain stream running through a deep 

 canyon with many oak trees. Perhaps a thousand feet above 

 the stream is the pine forest of the plateau of central Arizona. 

 These snakes were found in the stream, either on rocks or in 

 the water. Their general appearance is very different from 

 that of most garter-snakes. The absence of lines, the heavy 

 spotting, and the long, narrow head are not suggestive of 

 Thamnophis. 



