Chapter Xxxviii: the Rainbow Snakes

Large and Brilliantly Coloured, Burrowing Serpents, of the Genera

ABASTOR and FARANCIA

ALLEGED to be related to the tiny Worm Snake (Carphophis), the Rainbow Snakes are, from all external appearances, strikingly different from their small ally. They grow to a large size--five or six feet--and their handsome colouration is not eclipsed by any other North American reptile; intensifying the brilliant pattern, is the opalescent lustre of the scales.

With all their beauty of colouration these serpents are degenerate burrowers and seldom show themselves above the ground. The body is stout and powerful, but tapers gradually to a more slender neck and a head that is small, flat and not distinct. The eyes, placed well forward toward the snout, incline upward; they are dull and have a minute pupil, like a pin-hole. In proportion to the size, the tongue is exceedingly small.

By a single character, technically considered an important one, the Rainbow Snakes are divided into two genera. This is the structure of the plate or plates following the nose shield or rostral. With Abastor, there is a pair of these plates--internasals. Farancia has a single internasal plate. In every other way these snakes are similar. The teeth of the upper jaw are of about equal size. There is no preocular plate, the loreal plate forming a portion of the front border of the eye. The scales are smooth and in 19 rows; ventral plate divided. Both Abastor and Farancia, represented by single species, are confined to the southern United States; both are most abundant in Florida.

Following is a condensed formula to aid in identification:

A. Two internasal plates. Genus Abastor.

Blue-black, with three reddish stripes above.

Abdomen red, with rows of black spots.

RAINBOW SNAKE, A. erythrogrammus.

B. One internasal plate. Genus Farancia.

Blue-black; upright, vermilion bars on sides. Abdomen

vermilion. RED-BELLIED SNAKE, F. abacura.

Detailed descriptions: