The King Snakes 



THE MEXICAN KING SNAKE 

 Opbibolus micropbolis, (Cope) 



Very closely allied to the Western variety of the 

 Milk Snake group O. doliatus and its varieties, this Mexi- 

 can and Central American reptile exhibits an amazing de- 

 gree of variation. Further investigations, with large series 

 of specimens from various localities, may demonstrate that 

 it is but a Southern variety of the former snake doliatus. 

 It attains a length of about a yard and is of moderate thick- 

 ness. 



Colouration. The pattern of the phase occurring in northern 

 Mexico and the extreme southwestern portion of the United 

 States, is rather different from the ringed King Snakes of the 

 latter country. The colouration consists of rather narrow black 

 rings, each enclosing a very narrow and rather obscure ring of 

 yellow. The black rings are separated by very wide interspaces 

 of rich reddish-brown or scarlet fully four or five times the 

 width of the black. 



The head is black above, with a bright yellow band across 

 the rear portion. The chin is black, with a similar band. 



It will be appreciated that the red greatly predominates. 

 A superficial examination of the greater number of northern 

 Mexican specimens might result in the impression of a brick-red 

 snake, marked simply with rather narrow black rings at a con- 

 siderable distance apart; the faint yellow rings within the 

 black would be possibly overlooked. Curiously enough, 

 the poisonous Coral Snake (Elaps fulvius) occurring in the 

 districts inhabited by this distinct variety is marked in 

 precisely a similar fashion with one exception, and that 

 so obscurely delineated as not to detract from the strik- 

 ing resemblance of pattern. Instead of the black ring en- 

 closing a faint, streaky ring of yellow, the black rings of 

 the poisonous serpent are faintly bordered with yellow. At 

 a glance, it appears like the harmless serpent a brick-red 

 reptile with" black rings at considerable distances apart. With 

 both species the head is black, with a broad yellow band across 

 the temples. 



Dimensions. The measurements are of an adult female 

 specimen from the state of Sinaloa, in western Mexico: 



353 



