ART. 15 ANATOMY OF THE EARED AND EARLESS SEALS — HOWELL 77 



Caput 2 (figs. 9, 10, 23) in the Zalophus was the second part of the 

 flexor siiblimis of Miirie for Eicmefopia^. It arose from the medial 

 epicondyle of the humerus and from the medio-radial border of the 

 ulna from just distad of the coronoid to within a short distance of 

 the end of the shaft. Its short tendon partly fused with the deep 

 surface of that of the first division and when dissected free it was 

 fou.nd to <ro to digit 4 only. In Eumetopias the two heads of the 

 flexor sublimis joined and the tendon sent branches to the four 

 lateral digits. In this as in Zalophus the tendons of the first two 

 divisions were entirely separable from those of the third division. 

 In Arctocephalibs this part of the flexor complex was single and there 

 was fusion of the tendons with those of the third division. 



Ca.jmt 3 (figs. 10, 22) in the Zalophus and Murie's flexor pro- 

 fundus for Eu/metopias^ arose over the medial radius between the 

 biceps, pronator teres, interosseous membrane, and to within a short 

 distance of the distal end of the shaft. Its tendon sent branches to 

 the first three digits. In Eumetopias origin was from both the ulna 

 and radius, and two tendons extended to the pollex, two to the index, 

 and one to digit 3. 



Caput 4 (figs. 9, 22) in the Zalophus was a flexor pollicis longus, 

 innervated by a branch of the median nerve and homologically a 

 division of the flexor profundus, though whether morphologically 

 the same division of this muscle as its analogue in human anatomy 

 is not laiown. For Eumetopias, with origin the same, Murie termed 

 it palmaris longus primus, he believing that its tendon ended in the 

 palmar fascia. Of course, such may actually have been the case in 

 that genus, but the condition in Zalophus proves that it is a part of 

 the flexor communis. Origin was from the medial epicondyle ad- 

 joining the flexor carpi radialis. Its tendon passed in the super- 

 ficial flexor layer and near the base of metatarsus one it divided into 

 two, both branches inserting upon the pollex — presumably upon its 

 first phalanx. 



In Arctocephalus this complex was considerably different. It arose 

 by three heads which Miller termed as follows: A flexor sublimis, 

 from the medial epicondyle with tendon fusing with that of the 

 next; a flexor profundus, from the medial surface of the proximal 

 ulna; and a flexor pollicis longus, from the medial surface of the 

 shaft of the radius and slightly from the ulna, which joined the 

 common tendon of the flexor profundus, and this went to all five 

 digits. For Odohenus Murie reported it still different, with the 

 sublimis and profundus bellies partially fused, and a flexor pollicis 

 radiad. All of these were conjoined to a broad tendinous sheet with 

 five branches to the digits. The three divisions named are analogous 



