REPORT ON THE SEALS. 167 



It receives no fibres from the inner side of the coronoid process, for the upper end of the 

 internal condyle is at a greater distance from the coronoid and of greater length than in the 

 human subject. The bones of the forearm being naturally placed midway between pronation and 

 supination, a rotation of a quarter of a circle makes the hand prone. The mode of insertion in the 

 Phocinse and Arctocepludus is very different ; in the latter it is as is in human anatomy, but in the 

 former it is almost circular, and extends halfway across the inner surface of the radius near the 

 lower extremity. This strengthens the statement as to the absence of a pronator quadratus, for the 

 surface where it should be is partially occupied by the insertion of this muscle. In all the speci- 

 mens it is supplied by the median nerve, and has the usual action. 



The Pronator quadratus. — No evidence was got of its presence in the Phocinse and Arctocepludus, 

 although Humphry states that he found it but small, and Lucae inconsiderable. There is none in 

 the Otaria, but in the Walrus it is fairly developed. If I had only dissected young specimens I 

 should be sceptical as to its absence in the Phocinse, but in an adult Seal no fibres were seen where 

 the above writers have described it. The dissection in this specimen was clone by turning aside the 

 structures without removing any tissue. 



The Flexor carpi ulnaris arises from the inner surface of the ulna where the posterior border joins 

 the olecranon, and from the posterior border of the bone in its upper three-fourths, and is inserted 

 into the pisiform bone, from which the tendon passes on expanding and attaching itself to the bases 

 of the 3rd, 4th, and 5th metacarpal bones by joining the deep fascia adherent to them. 



In Arctoce'plmlus it arises from the inner side of the 3rd or posterior tubercle of the olecranon, 

 to the slightest extent from the commencement of the posterior border of the ulna below the 

 tubercle, and from the remainder of the upper half of the posterior border by an aponeurosis 

 common to it and the deep palmar muscle. It lies posterior to the deep palmar, with which it is 

 united so closely that no division is seen in the bellies of the combined muscles. It is covered 

 anteriorly by the tendon common to the deep palmar, and posteriorly by the aponeurosis of origin 

 from the posterior border of the ulna. About an inch from the lower end of the ulna it forms a 

 strong tendon, which is inserted into the pisiform bone as in the Phocinse, and into the strong 

 fascia over the base of the 5th metacarpal. In Otaria and Triclwchus it is very like the corre- 

 sponding muscle in Arctoccplwhts. 



All are agreed as to the pisiform being the chief point of insertion, but there are variations in the 

 ending of the tendon. From human anatomy we learn that there is close relationship between the an- 

 nular ligament and the flexor carpi ulnaris, and that the tendon terminates at the base of the 5th meta- 

 carpal, and this is nearly the arrangement I found in the Earless Seals ; in the Eared forms I am not 

 certain of the connection with the annular ligament. As the outer three digits in the Phocinre give 

 insertion to the flexor carpi radialis, and the bases of the three inner have this muscle fixed to them, 

 the whole series of metacarpal bases have each a flexor of the forearm acting upon them. Owing 

 to the posterior border of the ulna being arched with the concavity on the same side, and this muscle 

 passing in a direct line from the two extremities, the manus and bones of the forearm form two sides 

 of a triangle, with the pisiform as the apex. Hence this muscle must draw the hand to the inner 

 side, and also turn it a little to the outer side, as well as flex the manus. In all specimens it is 

 supplied by the ulnar nerve. It has the customary actions, and is in addition a powerful supinator 

 of the manus. 



The Abductor minimi digiti longus. — Humphry names it flexor minimi digiti ; Lucae, abductor 



