DR. J. MURIE ON THE ANATOMY OF THE SEA-LION. 565 
narrowing as they proceed downwards, still remain fleshy to the distal end of the ulna, 
where they lie directly on that bone, and at this place form a short, broadish tendon, 
widening distally, and which ultimately splits into four main divisions. 
The tendon given off the highest goes to the last phalanx of little, fifth, or outer 
digit, being joined by a small slip from the tendon of the fourth digit. A little below 
this first division the main tendon of the sublimis splits into three, which respectively 
supply the fourth, third, and second digits; but it is noteworthy that each of these 
three tendons is composed of two separate tendons, which, however, lie so close together 
as to have only the appearance of a single one. The tendon which goes to the index is 
partly fused with the tendon of the profundus muscle. 
The flexor profundus digitorum (F.p.d) is broad, flat, and so attached to the inter- 
osseous membrane and sides of the ulna and radius that its fleshy belly seems also to 
include the flexor longus pollicis muscle. 
At the carpal bones of the wrist-joint a strong, broad, flat tendon comes off super- 
ficially, and proceeds outwards and downwards, supplying the distal phalanx of the 
enormous thumb. This tendon it may be which represents the flexor longus pollicis. 
Below where the above pollicial tendon is given off from the main tendon of this 
compound muscle there occurs an aponeurotic expansion. This fascia is fully half an 
inch broad, and on its inner side joins the index tendon of the sublimis. To the inner 
side, and passing over the tendon spoken of, is a small tendon which goes to the third 
digit, joining at the distal end of the metacarpal with the tendon of the flexor sublimis. 
Another tendon is given off distally to this; and this one appears pierced by that of 
the flexor sublimis going to the index. This broad tendon goes to the proximal end of 
the proximal phalanx of the index. 
A third tendon is derived from the aforesaid fascial expansion, which also supplies 
the index, proceeding, however, to the furthermost distal phalanx. This tendon is 
joined by the flexor sublimis; and although it has the general aspect of a single broad 
tendon, in reality it represents the perforatus and perforans, the sublimis being more 
clearly divergent at the proximal end of the distal phalanx. 
Besides this junction with the sublimis, this profundus tendon has a part of the fascial 
tendon crossing and forming a binding slip; this portion joins the deep, broad, first- 
mentioned tendon of the index. Still another tendon is sent to the pollex ; and this one 
is inserted into the inner side of the proximal end of the first phalanx. 
Action of the deep Flexors.—tThe intercrossing of the tendons, and more or less union 
by fascial expansion of the sublimis and the profundus, and the intimate muscular and 
partly tendinous conjunction of the latter with the longus pollicis, produces a certain 
simultaneous movement of the whole palmar surface of the manus when the muscular 
bellies are contracted. This, added to the interdigital fibrous bridges and the extra- 
ordinary development of the superficial and deep palmar fascia, gives to this modified 
fore foot, under certain conditions, that powerful, flat, oar-like movement so capable of 
