144 
NATURAL HISTORY. 
[n. ZOOL. GAL. 
the rays of the fins (except the first of the dorsal and pectoral fins) be¬ 
ing soft, jointed, and usually divided at the end into several branches. 
This division has been separated into groups, according to the position 
of the ventral fin. 
Those of the first group, containing most of the fresh water fish, have 
the ventral fins situated behind the pectorals. 
The first family (Cyprinidze) have a small mouth, feeble and gene¬ 
rally toothless jaws, whose margin is formed by the intermaxillary 
bones; a strongly-toothed pharynx, and a soft rayed fin on the baok, 
but no adipose dorsal fin. These fish mostly feed on water-plants. 
Amongst them are the Carp ( Cyprinus), Tench ( Tinea), Bream 
( Brama), Barbel (Barbus), Loach ( Cobitis), and the Anableps ; the 
latter is peculiar for the eye being divided across, so that it appears to 
have four eyes, similar to the Gyrini among the water-insects. The 
female is viviparous. 
The family of Pikes (Esocnx®), also are without any adipose dorsal 
fin, and the upper jaws are edged by the intermaxillaries. In most of 
the genera, the dorsal fin is placed opposite the anal. They are gene¬ 
rally voracious, and prey on smaller fish. In many of these the jaws 
and palate are full of teeth, as in the common Pike (Esox lucius ) ; 
in others, as the Gar-Fish (Belone), the jaws are slender, and very 
much elongated. In one genus, the Half-Beak (Hemiramphus), the 
lower jaw r alone is elongated and the mouth oblique, and placed at 
its base. The Flying-Fish (Exocetus) belong to this family ; they 
inhabit the seas of -warm and temperate climates, and are peculiar for 
the great length of the pectoral fins, which enables them to suspend 
themselves in the air as long as the fins continue moist. On leaving 
the water to escape from the pursuit of their enemies in that element, 
they often become the prey of birds, which are continually on the watch 
to attack them. 
The Mormyri (Mormyrid.®) are fresh w r ater fish of Africa, like the 
Pikes, but they have a small mouth, and the gill-flap hid under the skin. 
The Siluroid Fish ( Silurid^) have a naked skin, in which large 
bony plates are frequently imbedded. They have often *an adipose 
dorsal fin, and their intermaxillaries form the margin of the upper jaw, 
their maxillaries being reduced to mere vestiges, or elongated into 
little beards. 
Many of these have the first ray of the pectoral fin very strong and 
bony, and the animal has the power of fixing it immoveably, so that it 
forms a dangerous weapon, and the wound inflicted by it is said to be 
venomous ; but this, perhaps, greatly depends on the liability of per¬ 
sons in warm climates to tetanus or locked jaw from penetrating 
wounds. They live chiefly on vegetable food, especially seeds. Their 
flesh is very fat, and much used as food; but that of some species, as 
the Shals ( Synodontes) of Senegal, is reputed to be dangerous. The 
skin of some of the genera, as the Callichtes ( Callichtes), is covered 
with four rows of large imbricated scales, which protect the body like 
scale-armour ; and others, as the Loricaria (Loricarice), have the body 
entirely covered with a hard coat, formed of angular scales. 
The Salmons ( Salmonid^:) have, like most of the Siluri, an adipose 
