This is the snake to which almost this book owes its origin, the specimens at the Zoological Gardens called ‘Moccasins’ tripping me up at the outset, as my preface sets forth. Holbrooke describes it as spending most of its time in the water, or about pond and river banks. It swims rapidly, and hundreds may be seen darting in all directions through the water. They are very common in the United States, and might have formed the ‘wreathed myriads’ on Lake Erie formerly. In summer they roost on the lower branches of trees, overhanging the water, like _Trigonocephalus piscivorus_, the true ‘water moccasin,’ or ‘cotton mouth.’ At the time of writing there are examples of both these at the Gardens, the harmless ‘moccasin,’ a rather handsome snake, and the venomous one (not there recognised as the well-known moccasin of the United States), so nearly black that we can account for its being occasionally called the ‘black water viper.’ It is probably _Tropidonotus_ which Parker Gilmore describes as ‘water vipers.’[73] At Vincennes in Indiana, he says, ‘On the side where some alder bushes grow in the water, I have seen, on a very warm and bright day, such numbers of water vipers twined round the limbs and trunks which margin the pond, that it would be almost impossible to wade a yard without being within reach of one of them. They certainly have all the appearance of being venomous; the inhabitants say, however, they are harmless. They feed principally on fish, frogs, and small birds.’ Of American water snakes, the anaconda deserves special mention. Of it Seba says, ‘Ce serpent habite plus les eaux que les rochers;’ and in its having the nostrils situated on the top of the head, and in possessing some other features in common with the _Homalopsidæ_, we are justified in calling it a water serpent, notwithstanding it is a true constrictor. ‘Mother of waters,’ the aborigines of South America call it. It is the _Boa aquatica_ of Neuwied, and _Eunectes murinus_ of Wagler, the latter name being the one most frequently used by modern herpetologists. Dumeril adopts it, _l’Eunect murin_, giving the origin of the generic name, _bon nageur_, from the Greek εὐ, _bien_, _fort_, and νηϰτής, _nageur_—_qui nage bien_. As to the meaning of the specific name _murinus_, there can be but little doubt, though some have attributed it to its mouse-coloured skin or spots. _Le mangeur de rats_, Bonnat called it; _le rativoro_, Lacepède. Seba, who was one of the first to describe it, says, ‘Il font guerre aux rats;’ and Bonnat, on his authority, says, ‘Il se nourrit d’une espèce de rats.’ ‘Serpent d’Amerique à moucheteur de tortue,’ Seba also describes it, and with ‘jolies écailles magnifiquement madrées de grandes taches, semblable de celles des tortues; taches semées sans ordres, grands, petits,’ etc. _Murinus_, therefore, clearly refers to its food, not its colour.