DR. J. MURIE ON THE ANATOMY OF THE SEA-LION, 539 
breast and between the flippers, where it is as much as 2 inches in depth. Upon the 
outer side of the chest it is not much over half an inch in thickness, and it thins 
considerably as it reaches the middle line of the back. The shoulders, the neck, and 
the head are clad by a continuation of the same material, which varies in thickness 
from a quarter of an inch to half an inch. Towards the median line of the abdominal 
region there is a layer of considerable depth; this is coextensive with the sterno- 
pectoral mass, but does not retain the thickness of the latter as it proceeds backwards. 
The continuation of the fatty investment upon the loins, buttocks, and hind limbs is 
much thinner than on the pectoro-abdominal parts, and assumes a thickness corre- 
sponding to the deposit on the cervical and dorsal regions. As it descends on the 
limbs the fat thins very considerably, and ere reaching the flippers almost entirely dis- 
appears—glistening areolar tissue taking its place, while the skin adheres closely and 
firmly to the tendinous ligamentary structures beneath. 
Fig. 2. 
Manner in which the Otary usually swallows its 
food. Sketched from the Society’s animal. 
<a 
So 
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III. THe Muscunar System. 
It may seem unusual that, in the account of the organs of locomotion, precedence 
should be given in the present instance to the muscular system instead of to the more 
solid bony axis. Such a course, I am aware, might either be defended or opposed on 
philosophical grounds. De Blainville’ remarks, “la multiplicité et la mobilité des 
piéces osseuses, coincidant avec la complication des parties musculaires, l’étude de ces 
derniers organes, qui dans la hiérarchie de l’importance relative des parties, occupent 
un rang supérieur aux os, inférieur au derme, est subordonnée a celle du squelette, de 
la forme duquel elle peut en général étre déduite.” 
For my own part I have been induced to deviate from the more common custom for 
several reasons,—among others, because the skeleton of Otaria is already known to 
some extent, and has been figured by Cuvier, De Blainville, &c., also because of the 
yery remarkable attitudes assumed both by the Otariide and Trichechide being in 
1 Cours de la Facult. des Sci. vol. ii., quotod in Meckel’s Anat. Comp. vol. vi. Append. p. 495. 
