[O.E.] A poisonous snake of America, with horny interlocking joiuts at the end of its tail with which it makes a rattling sound before striking its prey. The rattle is composed of a number of horny, button-like rings which fit loosely into one another and make a rustling noise when shaken rapidly. Some think that one new rattle is added with each shedding of its skin. The poisonous fangs take the place of other teeth in the upper jaw. These fangs are a pair of large teeth punctured by a tube from the poison-gland. They are laid back when not in use, but when the snake strike?, its prey the fangs spring forward and the poison flows from the poison-gland. Its bite is very poisonous, and it is very much dreaded. The best known are the diamond rattlesnake of South America and the common rattlesnake of North America.

RATTLESNAKE.