lower jaw at the same distance from the front, and are compressed rather than conical.
Mesoplodon bidens (Sowerby). Sowerby's Whale.—Average length from 15 to 18 feet, with 38 vertebrae and 10 pairs of ribs. The front slopes gradually to the beak. The front slopes gradually to the beak; the upper jaw is shorter and narrower than the under one, the projecting teeth on each side of the lower jaw being visible externally. The dorsal fin small; flippers the same. In colour it is described as black above and white below, the sides marked with vermicular white streaks. This species was first described by Sowerby from a specimen 16 feet in length, which was cast ashore in Elginshire. Since then others have been taken on the coast of Kerry and elsewhere in Ireland. Nothing is yet known of its distribution and habits.
Family Delphinidæ.
Genus Monodon, Linnaeus.
No dorsal fin and very small flippers. Head raised, with a small mouth and no beak. Two teeth in the upper jaw only. These are rudimentary and concealed by the gum in the female, but in the male, one (the left) is projected forward, in the shape of a long straight tusk, half the length of the body.[1]
Monodon monoceros, Linn. The Narwhal.—Averages 14 to 16 feet in length, with a single straight tusk 7 or 8 feet in length. In colour it is grey above, mottled with black; and white beneath, spotted with grey and black. Its usual haunts are between 70° and 80° N. lat. Three instances are on record of its occurrence on our coasts, namely, in Shetland, in the Firth of Forth, and near Boston, Lincolnshire. The word "Narwhal" signifies the Beaked Whale, from the Gothic nar, Icelandic ner, the beak.
Genus Delphinapterus, Lacépède.
Agrees with Monodon in having no dorsal fin, small flippers, a small round head, and no beak; but differs from it in having teeth in both jaws, none of which are prolonged externally. The tail is broad and powerful.
Delphinapterus leucas (Pallas). White Whale, or Beluga.—Attains a length of from 10 to 16 feet, and has 50 vertebræ and
- ↑ Occasionally, though rarely, both tusks are thus developed. There is a specimen in the Cambridge University Museum with two tusks, the left measuring 6 feet 7 inches, the right (which has been broken) 6 feet 1 inch.
