pipe-fish, according to Linnaeus, a genus belonging to the class of amphibians, and order of nantes, but arranged by Gmelin more properly under the class of piscis, and order of branchiognathi. The head is small; the rostrum somewhat cylindrical, long, and turned up at the point, where the mouth is placed, which is covered with a lid or valve. The gills are covered in the same manner. The body is covered with a strong crust, and has no ventral fins. There are eight species; the tetraconus, typhle, acus, pelagicus, aquaeous, ophidion, barbarus, and hippocampus. Three of these are found in the British seas, viz:

1. The barbarus, or longer pipe fish. One described by Sir Robert Sibbald, was two feet in length; that examined by Mr Pennant only 16 inches. The nose was an inch long, compressed sidewise, and the end of the lower mandible turned up; the aperture of the mouth was very small. The irides were red; behind each eye was a deep brown line. The body, in the thickest part, was about equal to a swan's quill, hexangular from the end of the dorsal fin; from thence to the tail, quadrangular. The belly was slightly carinated, and marked along the middle with a dusky line. Under the tail, commencing at the anus, is a fulvous or groove six inches and a half long, covered by two longitudinal valves, which concealed a multitude of young fish. On crusting this part, hundreds may be observed to crawl out.

2. The acus, or shorter pipe-fish, is thicker than the former, yet it has been seen of the length of 10 inches. The middle of the body in some is hexangular, in others pentagonal. The mouth is formed like that of the former; the irides are yellow; close behind the head are the pectoral fins, which are small and short. On the lower part of the back is one narrow fin; beyond the vent the tail commences, which is long and quadrangular. At the extremity is a fin round and radiated. The body is covered with a strong crust, elegantly divided into small compartments. The belly is white; the other parts are brown.

3. The ophidion, or little pipe-fish, seldom exceeds five inches in length, is very slender, and tapers off to a point. It wants both the pectoral and tail fins; is covered with a smooth skin, not with a crust as the two former kinds are. The nose is short, and turns a little up; the eyes are prominent. On the back is one narrow fin. This species is not viviparous; on the belly of the female is a long hollow, to which adhere the eggs, disposed in two or three rows. They are large, and not numerous. The synonym of serpent is used in several languages to express this fish: the French call one species orval, from a sort of snake not unlike the blindworm; the Germans call it mackerelblume; and the Cornish the sea-walker.

The Sea-horse, which was clasped by Arctedi under the Synagathus, is now, by later ichthyologists, arranged under Trichocetus; which see.