84 
their continuity with the borders of the epiglottis, proceeds to point 
out the differences presented by that of the Cats, and briefly observes, 
‘* Le Mangouste et la Civette ont la glotte comme les Chats.” He 
then describes a third variety of structure presented by the Bears, 
and mentions differences in the Racoon, the Badger, the Marten, the 
Otter, and the Coati, consisting merely of variations presented by 
the chord vocales, and in some the superaddition of sinuses, doubt- 
less only adaptive modifications to the different kinds of voice. 
In the foregoing observations nothing has been remarked with 
reference to the Seals, nor indeed is it absolutely necessary ; for the 
limits of a group, so distinctly marked and peculiarly modified, are 
never at all likely to be mistaken; but as this singular family is 
truly and essentially a portion of the order whose arrangement it is 
here my endeavour to elucidate, a few observations upon them may 
seem a little called for. Naturalists have long been accustomed 
to separate from the rest those which are distinguished externally 
by the presence of the small external ear, and the long riband-like 
processes of skin projecting from the tues of the hind-feet. These 
genera, Otaria and Arctocephalus, are also in their cranial characters 
the most distinctly separable from the rest, through which, with the 
exception of the Walrus, a great uniformity prevails, so that a men- 
tion of the characters in which the common Seal differs from those 
having external ears may perhaps suffice. Here there is no trace of 
a postorbital process, nor of an ali-sphenoid canal; the mastoid can 
scarcely be said to constitute a process ; it is swollen, and appears to 
form a portion of the auditory bulla, more or less connected with the 
tympanic portion, from which it is separated by a depressed groove 
running from the stylo-mastoid foramen backwards and a little in- 
wards. The paroccipital process is never large in any of the family, 
but it is always distinctly developed, and salient backwards. The 
Arctocephaline group are distinguished at once by their having a 
distinct postorbital process and an ali-sphenoid canal; the mastoid 
projects as a strong process, and seems, as it were, to stand aloof 
from the auditory bulla, which is small and rounded. The carotid 
canal has precisely the same course as that pointed out in the Bears 
and Dogs, while in the common Seal it enters rather more forward, 
and does not show itself again externally. The Arctocephalina have 
the orbito-sphenoids much compressed together anteriorly to the 
optic foramina, which almost appear to have coalesced into one: they 
are also remarkable for the strong development of a process on the 
anterior part of the rim of the orbit; this however will not well serve 
as a character, since it is apparent, though in a much less degree, in 
some of the larger species of the ordinary type, as the Stenoryhnchus 
leptonyx. The Walrus is a peculiar form which I should deem it 
advisable to constitute a distinct subfamily, since I cannot concur 
with Mr. Gray in associating with it the Halicherus gryphus, whose 
skull presents all the characters of the true Seals, the elevation in 
the nasal portion having no relation whatever with the immensely 
swollen upper jaw of the Walrus, which is necessitated by the enor- 
mous size of the canine teeth: in this animal there is no postorbital 
