As to the names of reptiles it is, of course, to the Romans that we are chiefly indebted, as in the case of reptile from _reptilus_, meaning creeping; and crocodile from _dilus_, a lizard. Serpent is also from the Latin _serpens_, creeping, and this from the old Sanskrit root, _sarp_, with the same meaning. This application of the idea of creeping is again found in the word snake, which originally came from the Sanskrit _naga_. Tortoise harks back to the Latin _tortus_, meaning twisted (hence our word tortuous) and came to be applied to these slow creatures because of their twisted legs. In its evolution through many tongues it has suffered numbers of variations; one of these being turtle, which we use to-day to designate the smaller land tortoises. Terrapin and its old forms _terrapene_ and _turpin_, on the contrary, originated in the New World, in the language of the American Redskin. _Cobra-de-capello_ is Portuguese for hooded snake, while python is far older, the same word being used by the Greeks to denote a spirit, demon, or evil-soothsayer. This name was really given to designate any species of large serpent. _Boa_ is Latin and was also applied to a large snake, while the importance of the character of size is seen, perhaps, in our words _bos_ and _bovine_. The word viper is interesting; coming directly from the Romans, who wrote it _vipera_. This in turn is a contraction of the feminine form of the adjective _vivipera_, in reference to the habit of these snakes of bringing forth their young alive. Lizard, through such forms as _lesarde_, _lezard_, _lagarto_, _lacerto_, is from the Latin _lacertus_, a lizard; while closely related is the word alligator by way of _lagarto_, _aligarto_, to alligator. The prefix may have arisen as a corruption of an article and a noun, as in the modern Spanish _el lagarto_,--a lizard. Monitor is Latin for one who reminds, these lizards being so called because they are supposed to give warning of the approach of crocodiles. Asp can be carried back to the _aspis_ of the Romans, no trace being found in the dim vistas of preceding tongues. Gecko, the name of certain wall-hunting lizards, is derived from their croaking cry; while iguana is a Spanish name taken from the old native Haytian appellation _biuana_.