[Illustration: PIPE FISH.]
The second division of the bony Fishes is quite small, including only
the Pipe-fish and the Sea-horses. These are distinguished by having the
gills divided into small round tufts and arranged in pairs—a structure
that is peculiar and different from that of any other Fishes. These
gills are enclosed under a large cover, which leaves only a small hole
for the escape of water which has served the purposes of respiration.
The Pipe-fishes belonging to this family possess a very strange organic
peculiarity. Their bodies are long, slender, and slightly tapering,
covered with plates set lengthwise; and the skin in swelling forms a
pouch near the tail into which the eggs glide to be hatched, and which
is afterwards a shelter for the young.
The Trumpet Pipe-fish has a small head and a long cylinder-shaped nose,
slightly raised at the end, and terminating in a very small mouth
without teeth. It is generally found in the Atlantic and the
Mediterranean.
There is still another Pipe-fish—the Fistularia—not often classed with
this family, but found among the spiny-finned Fishes, with an extremely
long nose in front of the head; this forms a long tube, in fact, at the
end of which is the mouth. This species is common at the Antilles. It
reaches a length of about three feet. It feeds upon crustaceans and
small Fishes, which it drags from the interstices of the rocks and
stones by means of its long pipe.