Page:The Zoologist, 3rd series, vol 2 (1878).djvu/28

6 North Atlantic and Arctic Oceans, and appears regularly in Davis Straits, and on the coasts of Iceland, Greenland, and Norway. It has been met with also off Kamschatka, the Aleutian Islands, and Labrador. The stragglers which have accidentally reached the British Islands have been found chiefly off the eastern coasts of Scotland and England; but solitary specimens have been procured also on the coasts of Cornwall, Lancashire, and Ireland.

This genus, to which the Common Sperm Whale belongs, is characterized by an enormous head, the length of which is about one-third of the entire length of the animal; no distinct dorsal fin; and teeth instead of whalebone. In the upper jaw the teeth are generally rudimentary or absent; but in the lower jaw they are numerous, large, and conical.

Physeter macrocephalus, Linn. Sperm Whale, or Cachelot.—Averages in length 60 to 70 feet (the female smaller), and has 50 vertebrae and 10 pairs of ribs. The head is of enormous size, and composed for the most part of cavities divided by a cartilaginous substance and filled with an oily fluid, which in its congealed state forms the spermaceti of commerce. The snout is abruptly truncated, and above it, and a little to the left, is a single blowhole. The upper jaw overhangs the under one by some four or five feet. Although there is no distinct dorsal fin, there is a marked protuberance not far from the tail. The colour is black above, shaded to grey beneath. It is native of the tropical and warmer temperate latitudes, from which it occasionally wanders both northwards and southwards. Several specimens have been secured at various times on the east coast of Scotland, and on the coasts of Yorkshire and Kent.

This genus is distinguished by the peculiar shape of the head, which is rounded in front, with a projecting beak and comparatively small gape; the skull with two large bony crests on the upper surface of the maxillaries; no teeth in the upper jaw, and those in