NARWHAL, a large porpoise which in habits the Arctic Ocean. It belongs to the family Delphiniche and was named Moitodon monoceros by Linnaeus. Its most striking char acteristic is the possession by the male of a very long, straight, spirally-grooved tusk, which projects forward from the left side of the upper jaw in line with the axis of the body. When full-grown the narwhal has a length of about 16 feet. The head is rounded, the back has a very low ridge instead of a fin and the pectoral fins are short and broad. The color of the body is gray above and white below, everywhere mottled and spotted with gray and black. The young are darker colored, while old individuals are often nearly white through out. The vertebral formula is as follows: Cervicals, 7; dorsals, 11; lumbars, 6; caudals, 26; total, 50. The cervical vertebra:, unlike those of other true porpoises, except the beluga or white whale, are all free. The skull is de pressed, with a broad rostrum.
The massive tusk or maxillary tooth of the narwhal is developed only in the male, and with rare exceptions, only on the left side of the jaw. Normally the corresponding tusk or tooth of the right side remains concealed in the maxillary bone during life. In females neither tusk is visible. All other teeth are want ing in adults of both sexes. Occasionally, both tusks are developed in males and in females as well. About 16 such heads have been pre
served, including one from Prince Regent In let, in the National Museum, Washington. The largest narwhal tusks are about eight feet long, with a girth of about nine inches at the base. They are hollow for a considerable proportion of their length.
The tusk is a secondary sexual character like the antlers of the stag, the spurs and comb of the cock, etc. It has been suggested that the narwhal makes use of the tusk to break the ice, to transfix its prey, or in combat, but these ideas lack confirmation.
When first introduced into Europe, the true origin of the tusks not being known, they were supposed to be the horns of the mythical uni corn. For a considerable time they were highly prized on account of their reputed medicinal properties, and are still made use of in China as a drug.
Narwhals occur in large herds or schools among the ice of the Arctic Ocean, northward of lat. 65° N. They migrate to higher latitudes as the ice recedes and return in the fall. Very rarely individuals stray southward along the coast of Europe as far as Scotland.
The narwhal resembles the bt..uga or white whale in many important characters, not shared by other porpoises, and forms with it a sepa rate sub-family, the Delohinapteritio.