Rattlesnake
the English name for any species of the American genus Crotalus, the tail of which is furnished with a rattle. Garman enumerates 12 species and 13 varieties, falling into two groups: (1) Having the upper side of the head covered with nine dermal shields; (2) having the shields behind the eyes broken up or replaced by small scales. The second group comprises the more formidable kinds, generally described as C. horridus and C. durissus. The first name was formerly applied to 8 B HEAD OF RATTLESNAKE A POISON GLAND B FANGS RATTLESNAKE the reptile extending from Paraguay and Chile through Brazil, into Mexico, and the latter to the North American rattlesnake. In recent American works this nomenclature is reversed. The poison of the rattlesnake is usually fatal to man, though fortunately they are sluggish, and never attempt to strike unless they are molested. They are widely distributed on the American continent.