60 
ROOM XI. 
Nat. Hist. 
In many of these the jaws and palate are full of 
teeth, as in the common pike ( Eeox lucius ); in 
others, as the Gar-Pike (Esox belone ), the jaws are 
slender, and very much elongated. In one genus, the 
Half-Beaks ( Hemiramphus ), the lower jaw alone is 
elongated and the mouth is oblique, and placed 
at its base. The Flying-Fish ( Exocetus ) belong to 
this family ; they inhabit the seas of warm and tempe¬ 
rate climates, and are peculiar for the great length of 
the pectoral fins, which enables them to suspend them¬ 
selves 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 ( Mormyrus ) are fresh water fish 
of Africa, which have a small mouth, and the gill-flap 
hid under the skin. 
The Siluroid Fish (Siluridce) have a naked skin, in 
which large bony plates are frequently imbedded. 
They have often a soft dorsal fin, and their intermaxil- 
laries edge the jaws, their maxiliaries forming only 
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 ve¬ 
nomous ; but this, perhaps, greatly depends on the 
liability of persons in warm climates to tetanus or locked 
jaw from penetrating wounds. They live chiefly on ve¬ 
getable food, especially seeds. Their flesh is very fat, 
and much used as food; but that of some species, as 
the Shals (Synodontis) of Senegal, is reputed to be dan¬ 
gerous. The skin of some of the genera, as the Callichtes 
('Callichtys ), is covered with four rows of large imbricate 
scales, which protect the body, like scale-armour; and 
others, as the Loricaria ( Loricaria ), have the body en¬ 
tirely covered with a hard coat, formed of angular scales. 
The family of Salmons (Salmonidce) has, like most 
of the Siluri , a soft, false, rayless, hinder dorsal fin, 
but 
