Variations and Relationships in the Snakes of the Genus Pituophis

From its wide range and varied habitat, its conspicuous size and pattern, and its abundance the genus Pituophis is probably one of the best-known genera of North American snakes. The purpose of the present study is to define the taxonomy status of the included forms on a structural and geographic basis, to determine their mutual affinities as far as is possible from the available material, and to assemble the accumulated data concerning them.