6 THE ZOOLOGIST. 
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. 
Family PHyseTeRID&. 
Genus Physeter, Linneus. 
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 vertebra 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 blow- 
hole. 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. 
Genus Hyperoodon, Lacépéde. 
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 
* These cavities are quite distinct from that of the cranium, which is situate 
beneath. 
