CLASS V. PISCES: OEDER 2. GANOIDEA. 
431 
the wing-like form of the pectoral fins. It is three to five feet long ; has a sting measuring three 
or four inches, and is found in the European seas ; common in the Mediterranean. 
Genus CEPHALOPTERA : Cei^lialojptera. — To this belongs the Sea Devil, or Ocean Yam- 
piEE, C. vamjnrus, sixteen to eighteen feet long, and eighteen feet wide, and occasionally weighs 
three or four tons. It seizes the cables of small vessels, and sometimes drags them along with 
great swiftness for several miles. Found on our southern coasts. 
ORDER 2. GANOIDEA. 
The tei'm Ganoidea is derived from the Greek ganos, splendor, and was applied by Agassiz to 
a large number of fishes, mostly fossil, distinguished by the angular form of the scales, these being 
composed of corneous or osseous substances, disposed one upon the other, and covered by a thick 
coat of enamel, and consequently resembling teeth. As a system more convenient for our pur- 
pose we adopt the classification of Miiller, applied to the living groups and divided into the Chon- 
drosfea, having a cartilaginous skeleton, and the Holostea, having a bony skeleton. 
THE CHOITDKOSTEA. 
Of these there are many fossil species, but of the living there are only two families, the 
Acipenseridce and the Spatularidm, 
Genus ACIPENSER : Acipenser, includes several species of Sturgeon ; these have an elongated 
body, and a funnel-shaped and 
~ - protrusible mouth, without 
« ' •'■^^ ,^:^£^^j^i^'3.iis^ of the head. 
The Common Sturgeon of 
THE COMMON STURGEON. EuROPE, A. StuHo, Is from slx 
to twelve feet long ; one weigh- 
ing four hundred pounds is mentioned by Pennant. It is found in the European seas and rivers, 
especially in the north ; its flesh is delicate and is compared to veal. Henry I., of England, 
declared it to be a royal fish and forbade it to be eaten at any table but his own. 
The Beluga, A. huso, attains the length of fifteen feet, and weighs from one to three thou- 
sand pounds. Its flesh is not greatly esteemed, but from its air-bladder an abundant supply of 
isinglass is obtained, in the Russian rivers, and also in the Caspian and Black Seas, where this 
fish is common. Other species, taken in large numbers in these regions, are the Sterlet, A. 
ruthenus, and the Scherg, A. helops. From the female roe of all these species of sturgeons, a 
substance called caviare is obtained, forming an important article of commerce in the countries 
around the Mediterranean. As a hundred thousand of the beluga alone are said to be annually 
taken in the Russian rivers, and as the roe constitutes often one-third of the whole weiffht of 
this fish, the extent of this trade may be easily calculated. 
The Short-nosed Sturgeon, A. brevirostris, found occasionally in the Hudson and other 
American rivers, i-esembles the European sturgeon, and may possibly be of the same species. 
The Lake Sturgeon, A. rubicundns, four to six feet long, is found in lakes Ontario and Erie, 
and in the Ohio River. 
The Sharp-nosed Sturgeon, A. oxi/rkynchus, is seven to eight feet long, and is found in the 
American Atlantic rivers. Other species are found in the northern and northwestern rivers of 
North America. 
Genus SPATULARIA : Spahdaria, includes certain species found in the great rivers of North 
America, of which the Paddle-Fish, S. folium, of the Mississippi, is the type. In these the skin 
is naked and the nose prolonged into a thin leaf-like appendage, sometimes nearly as long as the 
body. 
THE HOLOSTEA. 
This group includes several families most of which are fossil : of the Amiidce, which are clothed 
with small horny scales, usually covered with a layer of enamel, the Amia marmorata is the best 
