250 CETACEA 
floating on the surface of the seas it inhabits. Its genuineness is 
proved by the presence of the horny beaks of the cephalopods on 
which the Whale feeds. 
The oil contained in the great cavity above the skull, when re- 
fined, yields “spermaceti,” and the thick covering of blubber which 
everywhere envelops the body produces the valuable “sperm-oil ” 
of commerce; hence this animal has long been the subject of a 
regular chase, by which its numbers have been greatly diminished. 
Cogia.1—Teeth of the upper jaw absent, or reduced to a rudiment- 
ary pair in front; in the lower jaw 9 to 12 on each side, rather long, 
slender, pointed, and curved, with a coating of enamel. Upper 
surface of the cranium concave, with thick, raised posterior and 
lateral margins, massive and rounded at their anterior terminations 
above the orbits. Upper edge of the mesethmoid forming a pro- 
minent sinuous ridge, constituting a kind of longitudinal septum 
to the base of the great supra-cranial cavity. Rostrum not longer 
than the cranial portion of the skull, broad at the base, and rapidly 
tapering to the apex. Zygomatic process of the jugal styliform. 
Mandible with the symphysis less than half the length of the entire 
ramus. Vertebre: C 7, D 13 or 14, L and C 30; total 50 or 51. 
All the cervical vertebre united by their bodies and arches. Ex- 
ternal characters not well known, but, judging by the somewhat 
conflicting accounts of those that have had an opportunity of ob- 
serving them, the head is about one-sixth of the length of the body, 
and obtusely pointed in front; the mouth small, and placed far 
below the apex of the snout; the spiracle crescentic, and placed 
obliquely on the top of the head anteriorly to the eyes, and to the 
left of the middle line ; the pectoral fins are obtusely falcate ; and 
there is a triangular dorsal fin. 
The history of this genus is a good illustration of the difficulties 
in which the study of the Cetacea has been involved by the super- 
ficial manner in which it has been investigated. The first known 
example, a skull from the Cape of Good Hope in the Paris Museum, 
was described by De Blainville under the name of Physeter breviceps. 
This was afterwards with good reason generically separated by Gray. 
Until within a very few years ago only five other individuals had 
been met with, each of which had been described under a different 
specific name (viz. grayi, macleayi, simus, floweri, and potsit), and 
which are arranged by Gray in two distinct genera. The most 
careful examination of the description given of these specimens, or 
of the now numerous osteological remains available, fails to detect 
any differences beyond those which may be attributed to age or sex, 
and hence, according to our present knowledge, these six supposed 
species must all be included under one name, C. lericeps. This 
animal appears to attain the length of 10 feet when adult, and has 
? Gray, Zoology of Erebus and Terror, p. 22 (1846). Usually spelt Kogia. 
