Webster’s Revised Unabridged Dictionary · 1913
Black snake
Black′ snake′ (snāk) or Black′snake, n. (Zoöl.) A snake of a black color, of which two species are common in the United States, the Bascanium constrictor, or racer, sometimes six feet long, and the Scotophis Alleghaniensis, seven or eight feet long.
☞ The name is also applied to various other black serpents, as Natrix atra of Jamaica.