As this book has no scientific pretensions, and as its aim is rather to interest a large class of readers than systematically to instruct the few, I will not attempt a list of genera and species with all their perplexing names, if indeed a true list of all the now known species even exist. They are distinguished by the shields or plates on the head, and by the varying tails. Some have rattles so small as barely to entitle them to the name of _Crotalus_. Then, again, a new name is frequently adopted by the discoverer of a new feature; and a number of American genera, _minus_ a rattle altogether, are included among the _Crotalidæ_, an anomaly which will be presently explained. Here we have to do with only the rattlesnake proper, viz. the ‘Viper with the Bell,’ _Vipera caudisona_ of Tyson, and the _Crotalus_ of Linnæus. This word _Crotalus_, simply a rattle, from the Greek word _crotalon_, and the Latin _crotalia_ and _crotalum_, a kind of castanets, is as suitable as any that could possibly have been assigned to the snake; and most of the generic names are compounds of it: _Crotalophorus_, rattle-bearing; _Crotalina_, little rattle; _Crotaloidæ_; _Urocrotalon_, rattling tail; or simply _Crotalus_. Then the specific name more especially describes the snake in colour, size, character, locality, etc., as _Oregonus_, from Oregon; _Kirtlandii_, from Dr. Kirtland of Ohio, who first described that species; _horridus_, from the hideous, terrible character of this large snake; _miliarius_, a very small one; _caudisona_, sounding tail; and so on. Their geographical range is from about 45° north, to the Gulf of Mexico, Texas, and southward; and in South America to about the same degree of climate and temperature as in the northern latitudes. They are most virulent in the hottest seasons, the tropical regions, and according to their size; though, as is the case with other venomous snakes, a small species in hot weather and with a large store of venom may be more noxious than the largest in a half-torpid state and with a small supply of venom. There is one known as the ‘Prairie rattlesnake;’ another frequents the marshy districts of Ohio; another, the swamps of the Southern States along the coast; a fourth is known as the ‘Western rattlesnake;’ some of the 20 species described in the United States being more abundant in the mountainous regions, others near the rivers. In the wilder regions of Central and South America they also abound; but less is known of them where there are no United States Exploring Expeditions to record them. [Illustration] [Illustration] CHAPTER XVII. _THE RATTLE._