_Description._--This animal is of a fine shape: its size is rather above mediocrity, being about half a foot high, and the total length being twenty-seven inches, whereof nine form the tail. The general colour of the fur is of a drab brown, and it is neither coarse nor very fine. The head is elongated, oblong, about four inches long, shaped like that of a fox; the snout is narrow; the nose is black, notched, and granulated, furnished on each side with black whiskers, two inches long: there are three long black hairs, or _vibrissa_, above each eye, and a few shorter ones scattered behind them on the cheeks, chin, and tip of the lower jaw, which is white: the cheeks are whitish, and there is a white spot on the nape of the neck: the ears are large, broad, and white inside. There are three large, oblong spots, on the throat, breast, and belly; this last is the largest; that on the breast the smallest. The fore legs are shorter than the hind ones, and have, behind, three very long hairs or vibrissa: the feet and toes of all the legs are covered with long fur; the former have a dark brown or blackish ring, and the latter are of a dirty white: there are five long toes to all the feet, of which the inner one is the shortest; the nails are white, retractible, and shorter than the fur. The teeth are as in the genus _Mustela_, and white; those of the lower jaw are larger and stronger: the grinders are four on each side; they are broad, trifid, with the middle lobe sharp and very long: the tusks, or dogteeth, are very strong, curved, and approximated, leaving a very small place for the incisores, which are very small, very short, and flat; the two lateral ones on each side are situated diagonally, the second behind, and the two middle ones are only half the size of the others. The tail is bushy, particularly at the top, where there is a white pencil of long hairs; the brown of the remainder is darker than on the body. From the above accurate description, it will appear evident that this animal is very different from the common marten of North America. It must be a ferocious little animal, and very fierce; which is indicated by the strength of the teeth. ART. XVIII. _Natural History of the Scytalus Cupreus, or Copper-head Snake._ By C. S. RAFINESQUE.