396 MAMMALIA—GRAMPUS...SEA-UNICORN. 
and such is its violence in pursuit of its prey, that it will follon 1 shoak 
of small fish up a fresh water river, from whence it finds a diffiva ty to 
return. These creatures have been often taken in the river Thames, both 
above and below London bridge; and it is curious to observe with what 
dexterity they avoid their pursuers, and how momentarily they recover 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 porpoise yields about a hogshead of oil, and therefore renders its 
capture an object of consideration. 
It is said that, whenever a porpoise happens to be wounded, all the rest 
of its companions will immediately fall upon and devour it. 
THE GRAMPUS!} 
Is about twenty-four feet in length. It is a clumsy, unsightly fish, dark on 
the upper part, but very white below. The lower jaw is considerably wider 
than the upper. The back fin sometimes measures six feet. The grampus 
is an exceedingly voracious animal, which does not always spare even its 
own kind. Packs of them are said to attack the Greenland whale, like bull 
dogs, and tear off his flesh in masses. It, however, displays the utmost 
solicitude and affection for its young. Little oil is afforded by the grampus. 
It floats deep in the water, and would seldom be caught, did not its eager- 
ness for prey prompt it to rush into shailow waters, where it is killed, but 
not till it has made a desperate and formidable resistance. 
THE NWARWHAL,. OR SEA-UNICORN,? 
SeLpom exceeds twenty-two feet in length. Its body is slenderer than 
that of the whale, and its fat not so abundant. But this great animal is 
sufficiently distinguished from all others of the deep, by its tooth or teeth, 
which stand pointing directly forward from the upper jaw, and are from nine 
to ten feet long. In all the variety of weapons with which nature has 
armed her various tribes, there is not one so large or so formidable as this. 
This terrible weapon is generally fuund single; and some are of opinion 
that the animal is furnished with but one by nature: but there is at present 
the skull of a narwhal, at the Stadthouse at Amsterdam, with two teeth. 
The tooth, or as some are pleased to call it, the horn of the narwhal, is as 

1 Delphinus grampus, DesM. 
2 Monodon monoceros. 'This is the only one of the genus. The characteristics are one 
or two large tusks in the upper jaw; general form analogous to the dolphin’s ; orifice of 
the spiracles united on the top of the head; a longitudinal dorsal crest. 
