564 DR. J. MURIE ON THE ANATOMY OF THE SEA-LION. 
thick, muscular mass from the whole inner surface of the enlarged and flattened 
olecranon. The muscle below the olecranon process is intimately fused with the true 
flexor carpi ulnaris, the broad, flat, powerful bellies of the two forming a protuberant 
mass on the ulnar side of the limb. The direction of the palmaris Jongus tertius is 
oblique, the fleshy fibres stopping short about the middle of the arm, where a thickish, 
flat, ligamentous tendon, 13 inch broad, commences, and is continued downwards and 
across the wrist to the radial side of the pollicial metacarpal. The latter insertion 
extends from the carpus above the extensor ossis metacarpi tendon forwards to the 
distal extremity of the first phalanx, and, indeed, by continuity of fascia to the terminal 
phalangeal cartilage itself. At the wrist the deep flexor tendons pass beneath the 
oblique ligament. 
Flexor carpi ulnaris.—This is closely interwoven with the fleshy origin of the so-called 
palmaris longus tertius, and hardly to be separated from it above, but it is much more 
distinct and differently inserted below. It springs, along with the aforesaid muscle, 
from the olecranon, but chiefly from the sharp edge below the protuberance, and 
extends thence down the entire shaft of the bone; it forms, as it were, a septum between 
the anterior and posterior muscles of the forearm (/.c.w), which on the ulnar side con- 
siderably overlap the bone. In this way, having the great pollicial extensor closely 
applied to it on the one side and the great pollicial flexor on the other, the belly of the 
flexor ulnaris being wrapped between them as would the leaves of a book, the flexor 
carpi ulnaris is attached muscularly to the summit of the outstanding fusiform bone ; 
but a second strong tendon of insertion goes on to the deep palmar fascia at the root of 
the fifth metacarpal. 
The pronator radii teres (P.r.t) is short, broad, and well developed. It arises, in close 
adherence with and partially covered by the flexor carpi radialis, from the inner condyle 
and advances halfway down the radius. At the same time it occupies about half the 
breadth of that bone, which is unusually flattened to adapt itself to the peculiar com- 
pressed paddle-like extremity. 
The flexor carpi radialis, compared with some other muscles of the pectoral extremity 
of this creature, is of small bulk, although absolutely of fair size. Its origin, as usual, 
is the inner condyle, and in conjunction with the pronator radii teres. The muscular 
belly, which is fusiform, reaches halfway down the forearm; and the terminal long 
strong tendon dips beneath the deep palmar fascia and ligament, passing over the 
surface of the scaphoid and trapezium to be inserted into the proximal end of the 
first metacarpal (figs. 15, 26, 31, F.c.r). 
Flexor sublimis digitorum (F.s.d).—This muscle has two heads of origin, of about 
equal size, but neither are large. The one arises from the inner condyle, the capsular 
ligament of the elbow-joint, and from the inner head of the ulna. The other, second, 
shorter head arises from the ulna, its inner surface, below the olecranon, to as far as 
the middle of the shaft of that bone. At the latter place the two heads join, and, while 
