REVISION OF THE KING SNAKES. 73 



the white scales are nevertheless basally shaded with brown, and 

 this condition is evident on many of the ventral plates. A young 

 one from Fort Grant, Arizona, not far south of the range of typical 

 boylii, is indistinguishable from the latter species, and is identified as 

 yumensis only on locality. One from Fort Yuma is t>qncal of 

 yumensis in every respect. The evidence is of course inconclusive, 

 but favors the view that the young are like the jjarents. This will 

 be of interest in connection with the frequently noted fact that the 

 young of conjuncta are not like the adiUts, but like boylii. This is 

 in support of the distuictness of yumensis from conjuncta, and of the 

 derivation of the latter from boylii instead of from yumensis. 



A dark subocular spot originates in this form on the upper labials. 

 In ty})ical splendida the head is nearly all black, but across the center 

 of each labial there is a narrow vertical band of white. Westward 

 this band widens until the labials appear white with dark mutual 

 borders. But beneath the eye there is a strong tendency for the 

 black pigment adjacent to the suture between the third and fourth 

 upper labials to be retained, or, if lost, to be recovered. The result 

 is the conspicuous dark subocular spot characteristic of yumensis, 

 boylii, califoi^iae, and conjuncta. Some specimens, however, from the 

 vicinity of Yuma have been subject to such a general increase in 

 pigment that this spot is not recognizable. 



In brief, then, it appears that yumensis is not an mtergradational 

 condition between splendida and boylii, nor yet, as will be more 

 clearly brought out further on, is it identical with conjuncta of the 

 Cape Region of Lower California, but a recognizably distinct form 

 having a definite range that lies between the ranges of boylii and 

 splendida, and intergrading with both of these forms where their 

 ranges meet its own. 



