Mexican King Snake

Ophibolus micropholis, (Cope)

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.
Dimensions: The measurements are of an adult female specimen from the state of Sinaloa, in western Mexico:
Distribution: The distribution of this phase of the Mexican King Snake is the extreme southern portions of Arizona and New Mexico and northern Mexico generally. The species to which it belongs extends southward throughout Central America. The varieties have not been systematically treated by technical workers.

Very closely allied to the Western variety of the Milk Snake group--O. doliatus and its varieties, this Mexican and Central American reptile exhibits an amazing degree 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 thickness.

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 considerable 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 striking resemblance of pattern. Instead of the black ring enclosing 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.

Total Length . . . . . 36 inches.

Length of Tail . . . . . 5 inches.

Greatest Diameter . . . . . 3/4 inches.

Width of Head . . . . . 5/8 inches.

Length of Head . . . . . 1 inches.