Jew's-harp Snake

Trimorphodon lyrophanes, (Cope)

Colouration: Light gray; about twenty pairs of deep brown blotches on the back (to the base of tail); tail also blotched. There is an irregular row of blotches on the sides. Abdomen white; dark spots on the edges of many of the shields.
Dimensions: Total Length . . . . . 30 inches.
Distribution: Southern Arizona; Lower California.

Moderate in size--two and a half to three feet in length. Rather slender; neck very slender; head broad and very distinct--swollen at the temples, and with large eyes, the pupils elliptical.

On the top of the head is a large patch of deep brown, its outlines suggesting those of a jew's-harp.

Length of Tail . . . . . 6 inches.

Greatest Diameter . . . . . 5/8 inches.

Width of Head . . . . . 7/8 inches.

Length of Head . . . . . 1 1/8 inches.

The Genus Sibon: Formation and size similar to the preceding genus, but there is a single loreal plate in place of two as existing with Trimorphodon. Seven species comprise this genus. They inhabit Mexico and Central America. One extends north-ward into southern Texas.