CLASS V. PISCES: ORDER 3. TELEOSTEA. 
Genus UOTELLA: Motella. 
THE GREAT FORKED-BEARD 
THE THREE-BEAEDED EOCKLIXG. 
To this belongs the Three-be aeded Rockling, M. vulgaris. It is 
twelve to fifteen inches long, frequents 
rocky ground, feeds on aquntic insects, 
talces bait, but is not used for food, as 
the flesh smells unpleasantly in a short 
period after it is out of tlie water. 
Found in Europe. The Five-beaeded 
RocKLiNG, M. quinquecirrata, is also a 
European species. 
The Mackerel Midge, M.glaiica., is a 
beautiful little fish, an inch and a quarter 
long ; it dies instantly on being taken 
out of the water. From its njinute 
size and the multitudes in which it ap- 
peared, it was formerly thought to be 
produced by spontaneous generation 
from the froth of the sea, oi- the putri- 
faction of marine substances. 
The Silvery-Gade, M. argenteola, 
is two inches long. This and. the pre- 
ceding species are common in Europe. 
THE PLEURONECTID^. 
This term, derived from the Greet, pleuron, side, and neTco, to swim, means fishes that swim 
on the side, and is applied to those which are usually called Flat-fish. They are very peculiar in 
their appearance and form. They have a broad, flat body, margined almost throughout by long 
dorsal and anal fins; the head is 
singularly twisted, so that the 
eyes are both brought to one side 
of the body, and this, Avhich is al- 
ways uppermost, is usually of a dark 
color, and frequently spotted, wdiilst 
the opposite is always white. These 
surfaces are often regarded as the 
back and belly of the fish, but incor- 
rectly; the gill openings and the 
paired fins being situated on both 
surfaces, the pectorals a little behind 
the apertures of the gills, and the 
ventrals in front of those on the 
throat. The abdominal cavity is 
very small, and the anus opens under 
the throat, so that the whole body 
is nothing but an exceedingly com- 
pressed, disc-like tail. The mouth is small, and armed with small teeth, and in most species the 
skin is covered with ctenoid scales. 
The Flat-fishes swim with the dark side uppermost, and with a sort of undulating motion of 
the whole body ; they generally keep close to the bottom, where they feed upon small fishes, mol- 
lusca, worms, Crustacea, &c. Some species attain a large size; the Halibut is said sometimes to 
weigh as much as five hundred pounds ; a specimen, measuring seven feet six inches in length, 
three feet six inches in breadth, and weighing three hundred and twenty pounds, was taken in 
April, 1828, off" the Isle of Man, and sent to the Edinburgh market. The Turbot does not appear 
Vol. II. — 58. 
THE TDRBOT, 
