13 
Order IV. Physostomi. 
These are fishes with soft jointed fin-rays, the 
air-bladder is almost always provided with a pneumatic 
duct, and the ventral fins, if present, are placed behind 
the pectoral fins. The bones 
pharyngeal are 
separated, 
In the first two families, the body is snake- 
like, slimy, and naked, and the ventral fins 
are absent. The gill-cavities are large, but the gill- 
openings small, thus enabling the fish to live for a 
long time out of water. They are carnivorous fishes, 
and are found both in the sea and in fresh water. 
Family I. Gymnotida. The gill-openings are 
placed laterally over the small pectoral fins, Vent 
placed below the throat; and behind it is the long 
anal fin. Dorsal and caudal fins absent or nearly so. 
Plate XII. fig. e. Gymmnotus electricus, the 
Electric Eel, is common in the lakes and swamps 
of South America, where it grows to the length of 
six feet. Its electric discharge is sufficiently power- 
ful to kill small animals, and to disable large ones. 
The electric organs consists of two assemblages of 
prismatic cells filled with a jelly-like substance. 
Family I. Murenide. In the Eels, the vent 
is placed far from the throat, and there is usually 
a long dorsal fin. 
Plate XII. fig. f. Anguzlla fluviatilis, the Com- 
mon Eel, is dark green above with the sides paler, 
and the belly yellowish, with fine scales under the 
skin. It generally measures two or three feet in 
length, but sometimes attains a larger size. In warm 
weather they not unfrequently leave the water for 
a short time. 
Plate XII. fig. g. Murena Helena is spotted 
with brown and yellow, and has no pectoral fins. 
It grows to the length of three feet, and is common 
in the Mediterranean and Indian Oceans. This fish 
was greatly prized by the ancient Romans, and was 
reared by them in large fish-ponds, and fed on meat. 
In the remaining families of the Pysostomz, 
ventral fins are present, and are situated behind the 
pectorals. The majority of the species are found in 
fresh-water. 
Family I. Clupeida. Body long, with thin 
scales which easily fall off. Gape wide, air-bladder 
simple. They are marine fish which approach the 
coasts in vast shoals in the spawning season, and 
are caught by millions. 
Plate XVI. fig. f. Clupea harengus, the Her- 
ring, inhabits the northern seas as far as 67 degrees 
North; and the shoals appear on our coasts in sum- 
mer to spawn, The back is blackish, and the body 
silvery. They are eaten both fresh and salted. 
; Plate XVI. fig. g. Engraulis encrasicholus, 
the Anchovy, is smaller than the Herring, and may 
be recognised by its wide gape and projecting snout. 
It is common in the European seas, especially in 
the Mediterranean, from whence it is largely exported 
to all parts of the world. 
Family II. Silurid#. These are carnivorous 
freshwater-fishes, and are most abundant in the lakes 
and rivers of warm countrics. The head is flat and 
broad, and always provided with barbels. In many 
species the first ray of the pectoral fins is converted 
into a strong spine. There is frequently an adipose 
fin on the back. The skin is either naked, or covered 
with bony plates, 
Plate XVI. fig. d. S?/urus glanis, the only 
European species of the family, is also one of the 



largest of the European fresh-water fish, measuring 
upwards of six feet in lenght, and weighing 300 or 
400 pounds, There are two long barbels on the 
upper jaw, and four shorter ones on the lower jaw, 
It is greenish black above, and marbled with paler 
below; and the whole body is spotted with black. 
It frequents still water with a muddy bottom, and 
is found in the rivers of Eastern Europe. 
Family Ul. Cyprinidae. The air-bladder has a 
transverse division. The mouth is small, and only 
the lower pharyngeal bones are provided with teeth, 
and the fishes are probably carnivorous as well as her 
bivorous. The body is more high than broad, and 
is usually scaly, They are common in rivers and 
ponds. 
Plate XVL. fig. a. Nemachilus barbatulus, the 
Loach, is common in gravelly brooks, and lurks 
under stones. The skin is marbled with grey and 
white, and the mouth is furnished with six barbels 
It is about four inches long. 
Plate XVI. fig. b. Nemachilus fossilis is a 
larger fish about a foot long. It has ten barbels 
round the mouth, and is black above, with yellow 
longitudinal stripes on the sides, and the belly is 
dotted with orange and black. It is found in lakes 
and rivers with a muddy bottom, and has the curious 
habit of stirring up the mud before a storm. 
Plate XVI. fig. c. Codztzs tenia is a small fish 
about three inches long, which is not common in 
England. The back is grey, spotted with yellow 
and black, and there is a spine under each eye. 
Plate XVI. fig. h. Cyprinus carpio, the carp, 
is common in the rivers and lakes of Europe and 
Asia. It has four barbels, and there are 5 pharyn- 
geal teeth arranged in three rows. The scales are 
large, and dark green on the back, yellowish on the 
sides, and white on the belly. It is said to live to 
the age of a century, and to attain the lenght of 
four or five feet, and a weight of upwards of forty 
pounds. 
Plate XVII. fig. c. Carassius carassius, the 
Crucian Carp measures a foot in lenght and_ half 
as much in breadth, amid favourable surroundings. 
It has an arched back, and large greenish-golden 
scales. It has no barbels, and its habits are that 
of the common carp. It is common in many parts 
of Europe. 
Plate XVIII. fig. i. Carassius auratus, the Gold 
Fish, is a native of China, but is now domesticated 
in all parts of the world for the sake of its beauti- 
ful golden-red colour, which is gradually devoloped, 
as it grows, from the dark grey hue which it at 
first exhibits. It becomes very tame when kept in 
glass globes, but does not grow so large as in ponds. 
Plate XVI. fig. i. Ziznca vulgaris, the Tench, 
is a slimy fish with very small scales found in 
muddy water. It has only two harbels, and weighs 
from one to two pounds. There is a golden variety 
of this fish also. 
Plate XVIIL. fig. e. Rhodeus amarus is a small 
fish about three inches long, found in some parts 
of Eastern and Central Europe in running water. 
There are no barbels, and the male and female differ 
in colour; the latter is provided with,a long ovi- 
positor. 
Plate XVII. fig. a. Advamis brama, the Bream, 
has a broad flat body, and no barbels, and attains 
a length of two or three feet, anda weight of from 
