1 24 Phooxca;. MAilMALIA. Phocid^. 
Order VI.— PINNIPEDIA. 
This order of ampliibions mammals, though, for con- 
venience, here treated as a distinct group, cannot be 
regarded as zoologically equivalent to any of the fore- 
going ordinal divisions, inasmuch as it only represents 
a peculiar section of the Carnivora, properly so called. 
In accordance, therefore, witli the sj'stem indicated at 
the commencement of this work, the Pinnipeds or Seals 
are here considered separately. The most marked and 
obvious peculiarity in their organization, consists in 
the conversion of the limbs into paddles or swim- 
ming feet — the modifications of structure by which this 
change is brought about being best understood by 
an examination of the skeleton (Plate 34, fig. 114). 
Bearing in mind what we have already pointed 
out respecting the osteology of the typical carnivor, it 
will be noticed that the several skeletal elements of 
the seal are more or less attenuated, compressed, and 
shortened, according to circumstances. Thus, instead 
of the broad massive skull, we have a rather elongated 
cranium, associated with a movable spine, which is 
even more flexible than that of ordinary cats. The 
bones of the pelvis are particularly slender, and but 
feebly developed, while the shoulder-blades are, on the 
other hand, remarkably broad. There are no clavicles. 
The homologous arm and thigh bones, that is, the 
humeri and femora, are much shortened. The bones 
of the fore-arm are considerably flattened ; and, in the 
conformation of the hand, the adaptation of the limb 
for natatory purposes is eminently significant. It will 
be observed that the phalanges are drawn out, as it 
were ; and, diverging from one another, like the spokes 
of a wheel, thej^ form mutually-resisting supports for 
the interdigital webs. The hind paddles, with their 
membranous expansions, are similarly constructed, 
stretching out posteriorly in a horizontal direction. 
All the feet are pentadactylous, the toes of the anterior 
extremity becoming, one after another, shorter from the 
thumb outwards. The outer and innermost toes of 
the hind feet are the most extensively developed. The 
forward movements of the body upon land are pro- 
duced by a rapid succession of short shuffling or 
wriggling leaps, entirely due to the contraction of the 
muscles of the trunk, and altogether independent of 
the limbs, the latter only being emplo 3 ''ed in clambering 
up the sides of projecting rocks. Generally speaking, 
the bones are light and spongy in texture ; and this 
circumstance — when taken in connection with the boat- 
like form of the bodjq which terminates posteriorly in 
a short and conical tail, the oar-like limbs, the smooth 
adpressed fur, together with the flexible spine and 
powerful muscles — satisfactorily demonstrates how 
much care has been taken to render these creatures 
swift, easy, and vigorous swimmers. 
Family I.— PHOCIDAl. 
The true Seals have been divided into four sub- 
families or minor groups, but their differentiating 
characters are scarcely sufficient to warrant such an 
arrangement. The teeth are usually thirty-four in num- 
ber, of which there may be reckoned six or only four 
incisors above, and four or two below, together with 
four eanines, and twenty or twenty-two molars; all 
having the crowns armed with trenchant conical points. 
The tongue is smooth and bifid at the tip ; the stomach 
is simple, the intestinal canal being comparatively long. 
In connection with the liver, the posterior vena cava 
has a sacculated expansion, the use of which is to pre- 
vent the necessity of rapid respiration, thereby pro- 
longing the animal’s power of remaining under water. 
The venous blood is thus retarded in its course back 
to the lungs, until the animal rises for a fresh supplj' of 
air. During the action of diving, the nostrils are closed 
by a muscular sphincter. Under ordinary circum- 
stances seals can remain submerged from fifteen to 
twenty minutes; and it is stated that, during sleep, 
they will remain in this condition for as much as an 
hour, without coming to the surface to breathe. The 
shining, glossy, adpressed hairs are protected from an 
injurious action of the water, by an oily secretion which 
exudes from the skin. Their margins are sinuous, but 
the long, stout, horny whiskers are uniformly smooth. 
Seals are for the most part marine, but a few of them 
pass up the mouths of rivers to fresh-water streams, 
and even lakes. While at rest, they are usually seen 
reposing on the ledges of rocks, and basking in the 
sun ; and on being alarmed, they suddenly plunge into 
the water for security. These animals, as is well 
known, subsist principally on various kinds of fish ; but 
they will also devour crabs, molluscs, and other oceanic 
products. Fossil remains of seals occur in the miocene 
and pliocene deposits. 
THE COMMON SEAL {Plwca vitulina)—V\&tQ 12, 
fig. 40 — is an inhabitant of the northern seas generally, 
and was formerly very abundant all along the western 
coasts of the British islands, as well as those of France; 
now, however, it is comparatively scarce, except on the 
shores of Scotland, and its adjacent northern and 
western isles. The body of the seal is between four 
and five feet long, having an ashy or yellowish-grey 
ground colour, which is indistinctly spotted with light 
brownish-black patches ; it exhibits a cylindro-conical 
form, gradually diminishing in bulk from the region of 
the chest towards the short broad muzzle in front, and 
towards the rudimentary tail behind. The eyes are 
rather large, and protected by a few stiff hairs, forming- 
small eyebrows; the ears being fully-developed, and 
scarcelj^ visible. One of the most interesting peculiari- 
ties by which this species is distinguished, consists in 
the oblique disposition of the molar teeth, producing a 
slight overlapping of the ends; this remarkable charac- 
ter having been first pointed out by Professor Nilsson. 
The brain is largely developed — a fact which in some 
measure explains that high degree of intellectual 
manifestation, which the seal is capable of displaying. 
Though very timid in the wild state, and very difficult 
to approach with a gun, it is, nevertheless, extremely 
docile in a semi-domesticated condition. From the 
