ACANTHOPTERY'GH (from 4xasea, a thorn, and irrip4, a wing), in Zoology, one of the three primary divisions, or natural orders, of fishes. The fishes are divided into three orders—the Otondropterygii (from r6v3por, cartilage, and 7TT 11)4, a wing or fin), or cartilaginous fishes, without a solid bony skeleton; Acaathopterygii fishes having bony skeletons with prickly spinous processes in the dorsal fins; and Malacopterygii (maXaK6s, soft, and irripq, a wing), fishes with bony skeletons indeed, but with soft articulated radii in the dorsal fins. These divisions were first employed by Willughby and Ray. Cuvier divides the Acanthopterygious Fishes into fifteen natural fami lies, which he calls after the names of their typical or most common genera.
1. Percidte, including the common Perch, the Sea-Perch, the Barber of the Mediterranean, the Weevers, the Stargazers, and the Sea-Pike.
2. Triglidce, which include the Gurnards, the Flying-Fishes, the Bull Heads, the Miller's-Thumb, and the Sticklebacks.
3. Scialdda, which include the Maigres, the Stone-Perch, the Drum heads, the Red-Throats, and a number of other fishes less known.
4. Sparidte, including the Sea-Breams, the Spanish Bream, the Gilt Head, and Black Bream.
5. Menida', a small family whose species are not much known.
6. Squantipennes, including the Clautodons and other curious fishes, as the Coachmen, the Horsemen, and others.
7. Scomberidce include the Mackerel, the Tunnies, the Sword-Fishes, the Pilot-Fishes, the John-Dory, and the King-Fish.
8. Tcenider, including the Scabbard-Fish, the Hair-Tail, Red-Band Fish, and others.
9. Theta yes, including the Lancet-Fishes, and some other genera remarkable for their powerful cutting spines.
10. Anabadce include the Climbing Perch and other allied fresh water fishes.
11. Mugilida include the Gray Mullet, the Ramando of Nice, and some others.
12. Gobiodce include the Blennies, the Gobies, or Sea-Gudgeons, and the Dragonet.
13. Lopidadte include the Anglers, the Fishing-Frog, or Sea-Devil, and the Frog-Fishes.
14. Lain-tette include the Wrasses, or Rock-Fishes, the ' Old Wives of the Sea,' the Captains, and the Scams.
15. Fistularidte, include the Pipe-Mouths, the Snipe-Fish, the Sea Trumpet, or Bellows-Fish. ACANTHIPRUS (from 6KavOct, a thorn, and obpcf, a tail), a genus of Acanthopterygious Fishes. It contains a great number of species, many of which are remarkable for the beauty of their external forms, and the variety of their colours. They are distinguished from proxi mate genera by the form of the body and tail, which are exceedingly compressed ; by their trenchant teeth, denticulated like a very fine comb ; but above all by the moveable spines, edged and sharp like a for the Acanthuri the name of Doctors and Lancet-Fishea, by which they are well known to the English sailors and colonists. These animals have the mouth small, and the muzzle rather advanced. They are among the small number of fishes which live entirely upon vegetable substances, feeding only upon Fed, and other marine plants ; their intestinal canal is consequently longer and more complicated than in other species, and their flesh has a peculiar flavour, very different from that of fishes in general. The dangerous weapons with which nature has provided these otherwise harmless fishes are well calculated to defend them from the attacks of their enemies. They abound in all the tropical seas, both of the East and West Indies, and are never known to advance beyond the tropics; consequently they are unknown in the more temperate latitudes.