After the rattlesnake, the copper-head snake is the most dreaded in the northern states, being the next largest venomous snake: he is also more common in the cold parts, where the former is very rare. Strange as it may seem, this conspicuous and dangerous animal has escaped the notice of naturalists, and is not found described in Shaw nor Lacepede. Having seen two of them near Fishkill, in the summer of 1817, I endeavoured to describe them completely, and investigate their history. They were both killed in a meadow, and one of them while sleeping coiled up near a fence; a slight stroke of a rod was sufficient, as usual with venomous snakes. It appears that they are killed much easier than the innocent snakes; these are often seen to revive after an apparent death, and do not really die until the next sunset; while venomous snakes do not easily revive, particularly if the head is slightly bruised. This snake is known by a variety of names in different parts of the State of New-York, since he has every where attracted the attention of the inhabitants: these names are, _copper-head_, _copper-snake_, _chunk-head_, _copper-adder_, _copper-viper_, _copper-belly_, _pilot-snake_, _deaf-adder_, _deaf-snake_; and in New-England, by the names _rattlesnake's mate_ and _red adder_, &c. They have all been given in reference to his colour, or to some presumed peculiarities in his manners, &c. _Chunk-head_ is a vulgar expression, meaning thick-head or blunt-head. He has been called sometimes _pilot-snake_, on a false supposition that he was the pilot or guide of the rattlesnake; and he has been considered as deaf, because he is easily surprised, and does not appear to hear the noise of your approach. It belongs to the genus _scytalus_ of Daudin, &c., which differs from the _Boa_ of Linnæus, as the genus _Vipera_ does from _Coluber_, being provided with fangs. I have given to it the name of _Scytalus Cupreus_, which means coppered scytalus. The following definition of the species may be considered as comparative and characteristic. _Scytalus Cupreus._ Tail one-eighth of total length, with 45 caudal plates entirely brown; 150 abdominal plates, the last very broad; head oval, coppered above, yellow underneath; scales carinated on the back, which is coppered, with reddish brown rings cross-shaped; belly variegated of brownish.