SNAKES OF THE GENUS PITUOPHIS 



127 



the southern parts of New Mexico and Arizona, and to the north and 

 west in Arizona, and may be continued or reversed to California and 

 Lower CaUfornia, while in almost every case the character remains 



15 54 21 31 9 



32-35-25 

 31-35-25 

 31-35-23 

 29-35-23 

 33-33-23 

 31-33-25 

 31-33-23 

 30-33-23 

 50-33-22 

 29-33-25 

 29-33-24 

 29-33-23 

 29-33-21 

 27-33-23 

 27-32-24 

 30-31-23 

 29-31-25 

 29-31-24 

 29-31-23 



29-31-22 

 29-31-21 

 28-31-23 

 28-31-22 

 28-31-21 

 27-31-23 

 27-31-22 

 27-31-21 

 29-29-23 

 29-29-21 

 27-29-23 

 27-29-21 

 25-28-20 



Region No. 1 



Figure 58.— Geographic variation in number of scale 

 rows in PUuophis sayi affinis. 



Region , „ „ . _ 

 No. 1 2 3 4 5 



Figure 59.— Geographic variation in number 

 of ventrals in Pituophia sayi affinis. 



unchanged in northern New Mexico, or else the variational tendency 

 apparent elsewhere is reversed. Thus, in dorsal scale formula (fig. 

 58), ventrals (fig. 59), the sum of the ventrals and caudals, infralabials. 



