The Ring-necked Snakes 



THE SONORAN RING-NECKED SNAKE 



Diadophis fmnctaius. (B. & G.) AX^X. 



i-Vo 



From the other species of ring-necked snal<es, this serpent 

 may be told by the greater number of scale-rows and abdominal 

 plates. The scales are in seventeen rows; the abdominal plates 

 exist to the number of 183 to 237 (A. E. Brown), it is the largest 

 species of the genus, attaining a length of two feet. 



Colouration. — The typical form is dark bluish-gray above, 

 the abdomen yellow or reddish, with numerous, small, black 

 spots; the pale hue of the abdomen extends upward over the 

 first row of scales. On some specimens there are traces of a 

 yellowish or reddish collar; on the greater number this is absent. 



The variety arnyi is brownish-black, which dark hue extends 

 downward to the edges of the abdominal plates. 



Dimensions. — ^The length of an adult specimen is from twenty 

 to twenty-four inches. 



Distribution. — The Central and Western States — Illinois 

 southward to Arizona and thence to Vera Cruz. In the Central 

 region the species has been taken in the states of Illinois, Iowa, 

 Kansas and Missouri. It occurs in Colorado in the West. 



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