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Show 460 MR. ST. GEORGE MIVART ON THE [June 24, It arises from the occiput, and is inserted into the inner side of the dorsum of the scapula, being conterminous with the insertion of the serratus magnus. The omo-hyoid has been already described amongst the muscles of the head. Subclavius (fig. 3, S). This is an elongated muscle, like the precoracoidal cartilage to which it is attached. It arises from the ventral surface of the last-named cartilage, and is inserted into the upper part of the crest of the humerus, immediately opposite the summit of the biceps and between the insertions of the pectoralis, deltoid, and trapezius. Deeper flexor muscles of right forearm, the flexor longus being cut and reflected B. Biceps. C.B.2. Coraco-brachialis. F.B. Flexor brevis. F.L. Flexor longus. P. T. 1 & P. T. 2. Pronator teres. S. L. Supinator longus. 7!r. Triceps. Coraco-brachialis (figs. 4 & 6, C. B). This muscle consists of two parts. 1. The first part arises from the whole ventral surface of the coracoid, partly covered externally by the pectoralis, and partly appearing superficially between the second part of the pectoralis and omo-hyoid. It also arises from the postero-external margin of the coracoid. It is inserted into the humerus, between the implantation of the pectoralis and the origin of the biceps on the one hand, and the upper portion of the second part of the coraco-brachialis on the other. 2. The second portion of the muscle is thick and long. It arises from the posterior margin of the coracoid close behind the glenoid cavity; passing down, it is inserted into the shaft of the humerus to and at the internal condyle. The deltoid (fig. 3, D) is a larger muscle than the trapezius. It arises from the outside of the scapula, and is inserted into the crest of the humerus immediately outside and behind the insertion of the subclavius. Subscajmlaris. A very few and short muscular fibres, passing from just inside the postero-inferior margin of the scapula (close to the glenoid surface) to the adjacent part of the humerus, appear to represent this muscle. These are, however, difficult to distinguish from the adjacent coracoidal part of the triceps. Biceps (figs. 3, 4, & 6, B ) . This muscle, which is quite single, springs from the tuberosity of the humerus just below the in- |