xvi Introduction. 
Of the bony fishes the Acanthopterygii, or fishes with hard spiny fins, 
are divided into fifteen families, the principal of which are the perch 
family, the mailed cheek fishes, including the gurnards, the flying fish 
of the Mediterranean, and the sticklebacks, or jack banticles ; the 
mackerel family, including the tunny, bouito, and sword-fish ; the 
pilot-fish, the dolphin of the Mediterranean, so celebrated for the 
beauty of its dying tints, and the John Dory. Among the Malacop- 
teryyii abdominales, or soft-finned fishes, that have their ventral fins 
suspended from the abdomen, the most interesting are the carp family, 
the pike family, the flying-fish of the ocean, the salmon family, and 
the herring family, including the sprat, pilchard, and anchovy. 
The Malacopterygii sub-brachiati are soft-finned fishes, with the 
ventral fins beneath the pectorals ; the principal of which are the cod 
family, including the haddock, whiting, and ling; the flat-fish family, 
including soles, turbots, plaice, and flounders; and the suckers or 
lump-fish. 
1'he 3Ialacopterygii apodes are confined to the eel family. 
The Lophobranchii include the pipe fish, and other fishes of similar 
form. 
The Plectognathi comprise the very singular forms of the balloon- 
fish, the sun-fish, and other similar fishes. 
The Chondropterygii, or Cartilaginous fishes, are divided into three 
orders, viz. the Sturiones, or sturgeon family ; the Selachi, or sharks 
and rays, including the torpedo ; and the Cyclostomi, or lamprey family. 
The last two orders were included by Cuvier in a single one. 
THE MOLLUSCOUS ANIMALS 
Have no bones except their shells. Their sense of feeling appears to 
be very acute, but the organs for the other senses are either wanting or 
very imperfect. The blood is cold and white, and the heart often con- 
sists of only one ventricle; a few of them have imperfect lungs, but 
the greater number breathe through gills. They have all the power of 
remaining a long time in a state of rest, and their movements are 
either slow or violently laborious. Some of them appear incapable of 
locomotion. They produce their young from eggs, but some lay their 
eggs on a part of their own body, where the young are hatched. The 
following are Cuvier's six classes: — 
1. Cephalopoda, or Head-footed Mollusca. These animals are furnished 
with long fleshy arms or feet, proceeding from the head, winch 
is not distinct trom the boiy, and on which they crawl. There 
is only one order, which includes the cuttle-fish, nautilus, and 
beiemnites. 
2. Pteropoda, or Wing-footed Mollusca. These animals have two 
membranous feet or arms, like wings, proceeding from the 
neck. There is only one order, which contains six genera, the 
best known of which is the Hyalaea, the shell of which is com- 
monly called Venus's chariot. 
3. Gasteropoda, or Body-footed 31ollusca. All these animals crawl with 
the flat part of the body, which acts as a kind of sucker. There 
are nine orders in Cuvier's system. The common snail will give 
an idea of the habits of the class. 
