Crotalus horridus was first identified by Linnaeus in 1758. Pisani et al, 1972 conducted multivariate anaylsis of variation in Ch and came to the conclusion that characteristics tended to be clinal and recommended against recognition of the two subspecies. Brown and Ernst (1986) Brimleyana 12:57-74 countered that morphology in the eastern part of the range supported recognition of costal plains and montane subspecies. Reviewed by Collins and Knight in 1980.
[This information was gleaned from "Scientific ans Standard English Names of Amphibians & Reptiles of North America North of Mexico" Committee on Standard English and Scietific Names, SSAR, chaired by Brian L. Crother] ~Bill~