in ichthyology, a genus of fishes belonging to the order of cetaceans; the characters of which are: There are too very long, straight, and spirally twisted teeth, which stick out from the upper jaw; and the spiracle, or breathing-hole, is situated on the anterior part of the skull. There is but one species, the monoceros, or horned narwhal, which sometimes grows to 25 feet in length, exclusive of the horn; but the usual size is from 16 to 20. It is particularly noted for its horn or horns, as they are called; but which are real teeth. Of these there are always two in young animals; though the old ones have generally but one, sometimes none. From the circumstance of only one tooth being usually found, the animal has acquired the name of Unicorn Fish, or Sea Unicorn. They inhabit the northern seas, from Norway to within the arctic circle: they are plentiful in Davis's Straits and the north of Greenland; where the natives, for want of wood, make rafters of the teeth. From the tooth or horn may be distilled a very strong oil volatile: the scrapings are esteemed alexipharmic, and were used of old in malignant fevers and against the bites of serpents. The use of it to the animal seems to be chiefly as a weapon of offence, and a very powerful one it appears to be: there are many instances of its having been found in the bottoms of ships which returned from the northern seas, probably owing to the animal's having mistaken the ship for a whale, and attacked it with such fury as not to be able to get out the weapon from the wood. It may also serve as an instrument to loosen and disengage from the rocks or bottom of the sea the sea plants on which it feeds. These fishes swim swiftly, and can only be struck when numbers happen to be found together, and obstruct their own course with their teeth. Their skin is white, with black spots on the back, and has a great quantity of blubber underneath.

The tooth of this animal was in old times imposed upon the world as the horn of an unicorn, and sold at a very high price. The heirs of the chancellor to Christian Friisius of Denmark, valued one at 8000 imperials. There is a magnificent throne made of this species of ivory for the Danish monarchs, which is still preserved in the castle at Rosenborg. The price of this material was superior to gold.