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Show 582 PROF. M. WATSON O N THK [June 20, The obliquus externus abdominis arises in Proteles from the last ten ribs. In H. crocuta it arises from the last eleven ribs. Muscles of the Fore Limb. In Proteles the pectoralis major resembles that of H. crocuta, but takes an additional origin from the abdominal aponeurosis. The separation of the muscle into two strata is more complete in Proteles than in H. crocuta. In the former the posterior fibres form almost a separate muscle, which has a special insertion into the great tuberosity of the humerus ; while the anterior fibres are inserted, as in H. crocuta, into the whole length of the shaft of that bone. In Viverra the muscle is divisible into three strata, and its insertion is confined to the upper third of the humerus. The deltoid muscle is not divisible into two parts as in H. crocuta, the two portions being quite continuous with one another. The levator humeri proprius (Douglas) of Proteles differs from that of H. crocuta inasmuch as it is inserted into the upper end of the radius and more especially of the ulna, and not, as in H. crocuta, into the lower end of the humerus. In this respect Proteles differs likewise from H. brunnea and from Viverra (according to the observations of Young x ) . According to Macalister2, however, in Viverra this muscle extends, as in Proteles, as low down as the upper end of the radius. The levator scapula in Proteles is chiefly inserted into the fascia covering the infraspinatus, and to a less extent into the acromion process. In H. crocuta the reverse is the case. The teres minor in Proteles is quite inseparable from the infraspinatus. In this respect Proteles differs from both H. crocuta and Viverra. The brachialis anticus in Proteles is inserted partly into the radius and partly into the ulna. In H. crocuta it is inserted into the ulna alone. The triceps of Proteles differs from that of H. crocuta in the possession of a fifth head. This fifth head forms the most superficial part of the muscle, and consists of a narrow fleshy band which arises from the middle in length of the spine of the scapula, where it lies superficial to the infraspinatus. It passes downwards parallel to and in contact with the glenoid head of the triceps, and is inserted into the olecranon process along with the rest of the muscle. This head is absent not only in II. crocuta but in Viverra. The supinator longus is entirely absent in Proteles, not even being represented by a tendinous band as in H. crocuta. In Viverra the muscle is quite distinct, although of small size. The extensores carpi rudiales resemble those of H. crocuta inasmuch as they are partially fused together. In this respect Proteles differs from H. striata, in which these muscles are quite distinct. The tendon of the extensor carpi ulnaris in Proteles gives off a 1 Loc. cit. a «rpjjg Muscular Anatomy of the Civet and Tayra," Proc. Roy. Irish Acad. vol. i. ser. 2, p. 506. |