OF FISH. 
261 
cover their breath above the water. It is usual to spread 
four or five boats over the part of the river where they 
are seen, and to fire at them the instant they rise. One 
porpus yields about a hogshead of oil, and therefore 
renders its capture an object of consideration. 
White Shark. ( Squalus . PI. 44.) The white shark 
has six rows of teeth, hard, sharply pointed, and of a 
wedge-like figure; these, he has the power of erecting 
and depressing at pleasure: when at rest, they are quite 
flat in his mouth; but when his prey is to be seized, they 
are instantly erected by a set of muscles that join them 
in the jaw. Thus, with open jaw, goggling eyes, and 
large and bristly fins, agitated like the mane of a lion, his 
whole aspect is a striking picture of the fiercest, deepest, 
and most savage malignity. These creatures are the 
dread of sailors in all the hot climates, where they con- 
stantly attend the ships, in expectation of what may drop 
overboard; and if, in this case, any of the men have that 
misforture, they must inevitably perish. 
In the pearl fisheries of South America, every negro, 
to defend himself against these animals, carries with him 
into the water, a sharp knife; which, if the fish offers to 
assault him, he endeavours to strike into its belly; on 
which it generally swims off. The officers who are in the 
vessels keep a watchful eye on these voracious creatures; 
and when they observe them approach, shake the ropes 
fastened to the negroes to put them on their guard. — 
Many of them, when the divers have been in danger, 
have thrown themselves into the water, with knives in 
their hands, and hastened to their 4<jf ence > but too often 
all their dexterity and precaution have been of no avail. 
Sturgeon. ( Accipenser Strurio. Lin. PI. 44.) 1 hough 
this fish from its size and construction appears formida- 
ble, yet it is perfectly harmless; the body, which is 
from six to eighteen feet in length, is pentagonal, armed 
from head to tail with five row's of large bony tubercles, 
each of which ends in a strong recurved tip; one of these 
is on the back, one on each side, and two on the margin 
of the belly. The snout is long, and obtuse at the end, 
and has the tendrils near the tip. The mouth, which is 
