NARWHAL. 
93 
with numerous formidable teeth, high pointed back-fin, and 
broad rounded flippers. “ Killers are found in almost all seas, 
from Greenland to the Antarctic, and are distinguished from 
their allies by their ferocity, being the only Cetaceans which 
habitually prey on warm-blooded animals ; for though fish form 
part of their food, they also attack and devour Seals, Porpoises, 
Dolphins, and combine in packs to hunt and destroy full-sized 
Whales. A model of a female caught at the mouth of the 
Humber, in November 1885, is exhibited near the north end of 
the gallery, and alongside the skeleton of this same female. 
The Irawadi Dolphin, Orcella fluminalis, of which a skeleton 
is exhibited, is a small species found in the Irawadi River, 
from 300 to 900 miles from the sea. 
The Beluga, or White Whale, Deljyliinajjterus levcas^ so called 
from its almost pure white colour, and about 12 feet long, is 
abundant in the Arctic seas, and extends as far south on the 
American coast as the river St. Lawrence, which it ascends for 
a considerable distance. On rare occasions it has been seen on 
the coast of Scotland. It has no back-fin. A model made on 
the skeleton is exhibited. 
The Narwhal, or Sea-Unicorn, Monodon monoceros^ resembles 
the Beluga closely in everything but its teeth, as will be seen 
by comparing their skeletons. The Narwhal has only two 
teeth in the adult state, both of which lie horizontally in the 
upper jaw. In the female these remain permanently concealed 
within the bones of the jaw, so that this sex is practically 
toothless ; but in the male, while the right tooth remains 
similarly concealed and abortive (as shown in the skeleton by 
removal of part of the bone which covered it), the left is 
immensely developed, attaining a length equal to more than 
half that of the entire animal, projecting horizontally from the 
head in the form of a cylindrical or slightly tapering pointed 
tusk, with the surface marked by spiral grooves and ridges. 
In very rare cases both teeth are fully developed, as in the 
skull exhibited near the skeleton. Narwhals inhabit the Arctic 
regions, where they are comparatively abundant and gregarious, 
and feed on various cuttlefishes, small fish, and crustaceans. 
The use to which they put the tusk (often spoken of as the 
