diadophis

Century Dictionary and Cyclopedia

1. n. A genus of Colubridæ, having the head distinct, the body slender with smooth scales, the postabdominal scutella bifid, the subcaudals all divided, the cephalic plates normal, with a well-developed loral, 2 postorbitals, 2 anteorbitals, and 2 nasals, between which latter is the nostril. The best-known species is D. punctatus, the ring-necked snake, found in many parts of the United States, a very common and pretty snake, quite harmless, of small size, and dark-green color above and yellowish below, with a yellowish ring round the neck. There are several others.

WordNet 3.0

1. n. a genus of reptiles of the family Colubridae including ringneck snakes