REPORT ON THE SEALS. 157 



In Arctocephahis it is under cover of the deltoid, and is triangular in form. It arises from the 

 dorsum of the scapula, anterior to the tendon of origin of the long head of the triceps, and the 

 dorsi-epitrochlear muscles ; from the posterior border of the scapular spine, beneath the origin of 

 the deltoid ; from the dorsal surface of the capsule surrounding the neck of the scapula. It 

 crosses the dorsal surface of the shoulder-joint as a round tendon, is closely adherent to the 

 capsule, and is inserted into a pit at the junction of the posterior bolder of the great tuberosity 

 with the head of the humerus, below the pit for the posterior part of the supraspinatus. In 

 Otaria it penetrates the capsular ligament, and strengthens it. In Trichechus it overlaps its large 

 fossa. In the Phocinre it is supplied by the suprascapular nerves from the 6th cervical. In 

 Arctoccplmlus by the circumflex. In the Phocinre and Arctocepkalus it rotates the fore-limb 

 backwards. 



The Teres minor is a scanty muscular band which arises from a narrow line anterior to the 

 long head of the triceps, and posterior to the infraspinatus. It is inserted into the capsule of 

 the shoidder-joint ; and into the anterior side of the great tuberosity of the humerus, below the 

 infraspinatus. In Arctocephahis it is not found. In Otaria the fibres are lost upon the capsular 

 head of the triceps, and in Trichechus it is rather indistinct, if present. 



In Arctocephalus the infraspinatus has the same action as the teres minor in the Phocinse, and 

 I infer that the infraspinatus in Arctocephalus does the same work as the teres minor, and that the 

 posterior part of the supraspinatus in the latter is functionally the same as the infraspinatus 

 of the Phocinse. In the Phocinre it is supplied by the circumflex, and is a feeble rotator outwards. 



The Teres major is a triangular muscle, lying on the posterior angle and dorsal surface of the 

 scapula. The latissimus dorsi covers a portion of it. It arises from the scapula posterior to the 

 origins of the dorsi-epitrochlear and the long head of the triceps, to one inch from the glenoid 

 cavity ; and from the dorsum of the cartilaginous plate. About the middle of the posterior 

 surface it becomes muscular, and the lower margin of the tendinous surface of the inner half blends 

 with the inner tendon of the latissimus dorsi. It is inserted into the inner border of the humerus 

 below the subscapulo-capsularis for half an inch ; and slightly into the great bicipital hollow. 



In Arctocephalus it is rectangular and arises from the ventral surface at the posterior angle of the 

 scapula, from the lower surface of the tendinous area which gives origin to the subscapularis 

 anteriorly, from the posterior costa, and from the posterior angle by muscular fibres ; a few fibres 

 come from the posterior angle of the cartilaginous rim, and from the serratus magnus. The 

 latissimus joins it along its posterior border ; anteriorly it blends with the subscapularis outside of 

 its origin for an inch. It is inserted into the middle third of the inner border of the shaft of the 

 humerus, and slightly into the great bicipital groove, below the episubscapularis. In Otaria and 

 Trichechus it is inserted from the middle of the shaft upwards to the internal condyloid ridge 

 with the dorsi-epitrochlear and first head of the triceps. 



With the assistance of the human scapula a better reading of those of the Phocinre and the 

 Arctoccphali is obtained. In man there is an axillary border which has an adjacent surface on 

 the dorsum of the bone, and this is cut off from the infraspinous fossa by a ridge running from 

 the glenoid to the inferior angle. The adjacent surface is divided into two, the upper half for the 

 teres minor, the lower for the teres major. This ridge is present in the Phocinre and the 

 Arctoccphali, but is modified ; in the former the glenoid third on the dorsum is well marked, over the 

 remainder is faint, but on close examination can be seen and felt; and it ends at the vertebral border 



