38 TROPIDONOTUS NIGER. 
Cotour. The whole superior surface of the animal is dusky-grey; the throat 
milky-white; the abdomen and under surface of the tail is slate colour, more or 
less relieved in the centre by milky-white. 
Divenstons. Length of head, 1 inch; length of body, 20 inches; length of tail, 
8 inches: total length, 2 feet 5 inches. In the specimen here described, there were 
143 abdominal plates and 64 pair of sub-caudal bifid plates. 
Hairs. The Tropidonotus niger feeds on small reptiles, as frogs, toads, &e., 
and is a harmless snake, although commonly considered venomous. 
GuocrapuicaL Distrisution. The Tropidonotus seems to be peculiarly a 
northern animal, never having as yet been observed in Pennsylvania, though 
abundant in the New England states, where it is known under the name of Water 
Adder. The beautiful specimen, from which the accompanying plate was taken, 
was sent to me by Dr. Storer, of Boston, who informs me that it was captured at 
Cambridge. 
Generat Remarks. This animal in New Hampshire represents the Tropido- 
notus fasciatus of the south, and Tropidonotus sipedon of the middle states. 
