DR. J. MURIE ON THE ANATOMY OF THE WALRUS. 415 
by their being strained into an unnatural position so far as the free action of the joints 
are concerned. 
The locomotion of the Sea-lion (Otaria) on terra firma resembles in most respects 
that of Trichechus; but the latter has the ankle-joints freer, consequently the hind foot 
possesses greater power of step. To make up for this deficiency, however, Ofaria is 
remarkably nimble in the use of the linked hind quarters and legs. 
Capt. Beechey’ says, ‘‘ the gallop? of a Sea-Horse is probably the most awkward motion 
that is exhibited by any animal, from the great difficulty they experience in bringing 
the hind feet forward, and the great disproportion between the length of their bodies 
and their legs.” 
When straddling about in the enclosure, it never seemed to have such a long laterally 
compressed body as is most markedly the case in the Sea-lion; on the contrary, it 
exhibited great breadth of body compared with its length. 
When the very lean carcass, however, was skinned, the shape altered manifestly. It 
came out of its tegumentary envelope far more like O¢aria than with the felt on. Still 
differences can be named: for instance, the neck is shorter in proportion to the body 
than in it; the laryngeal prominence is less protuberant, consequently this affects the 
contour-line of the neck; the thorax, though deprived of its massiveness by absence of 
skin, is yet not quite so laterally compressed or narrow; the fore limb looks shorter, 
because of the reduction of the pollex, this digit in Ofaria being of enormous length, 
even as compared with its ally Trichechus; and, lastly, the hind feet, either expanded 
or contracted, are more dumpy. ‘The Seal (Phoca), when on the ground, has a totally 
different comportment from either; for as it stretches its hind limbs stiffly backwards and 
tucks its fore ones alongside its chest, the body acquires an elongate cylindrical shape. 
3. Dimensions.—Before discussing other matters appertaining to the exterior build, 
I subjoin some measurements taken from the dead body :— 
1. Extreme length, viz. from the muzzle to the tip of the hind 
extremity when this is stretched backwards 
. Length from the muzzle to the tip of the tail . 
. Length from the muzzle to the shoulder joint . 
. Girth round the neck in front of the shoulder . 
. Girth round the thorax behind the anterior limbs : 
These last two measurements are only approximative, by reason 
of the loose condition of the skin and subcutaneous tissues. 
6. The greatest stretch or transverse diameter of the fore limbs 
when the body is laid back downwards . . ..... 4 8 
1 Voyage of H.M.S. ‘ Blossom,’ 1825-28. 
3 « Gallop” does not perfectly express the action ; physiologically speaking, it is acanter. The former differs 
from the latter in the fore feet being both put to the ground at the same time, which is not the case with the 
Walrus. Vide Johannes Miiller’s ‘ Physiologie.’ 
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