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Show 816 MR. J. B. PERRIN ON BALANOPTERA ROSTRATA. [DeC. 6, This arrangement differs somewhat from that described by Carte and Macalister. There was no palmaris longus. The suprascapular ligament is triangular in shape, 2\ inches long, and attached by its base to the upper border of the scapula, reaching as far outwards as the coracoid process. The omo-hyoid muscle is attached to the whole length of this ligament. The suprascapular notch was oval in shape, the long axis of the ellipse running parallel with the supraspinatus muscle, measuring 2 inches ; its vertical axis measured 1| inch. It transmitted the large suprascapular nerve, and was closed in posteriorly by the supraspinatus muscle. The Scapulo-humeral Articulation.-This articulation is a perfect enarthrosis, provided with a complete capsular ligament, stronger on the ventral than the dorsal aspect of the joint. It is not perforated by the tendon of the subscapularis muscle, as described by Carte and Macalister in their specimen. Although the tendon of the subscapularis lies in close contact with it, it could be readily detached by careful dissection, without any appearance whatever of perforation. The capsular ligament was strengthened on its dorsal aspect by a strong ligamentous band, which was attached proximally by a broad expansion to the margin of the glenoid and the adjoining surface of the base of the coracoid; from this wide attachment the ligament rapidly narrowed to a strong and thicker band, about one quarter of an inch wide, which passed across the capsular ligament to be inserted into the humerus immediately to the ulnar side of the infraspinatus tendon, and behind tbe tendon of insertion of the deltoid. This articulation has a large and somewhat loose synovial membrane, which could be readily demonstrated by dissection. From the ventral aspect of the capsular ligament a strong tendinous process, about au inch and a quarter wide, arose, passing behind the subscapular muscle, and joined the upper fibres of insertion of the teres major muscle (fig. 2, Pf). No distinct muscular fibres could be detected in this fascial process, though it is evidently homologous to a peculiar muscle which is occasionally found in the human subject. The humero-cubital articulation is formed by the direct apposition of the slightly convex and transversely flattened distal extremity of the humerus with the flattened and but slightly concave proximal ends of the radius and ulna, the latter bone having on its postaxial border its cartilaginous olecranon prolonged backwards on to tbe humerus somewhat beyond the remainder of the bone. There was but very slight movement in this articulation, the greatest extent being allowed at tbe point of the recurvation of the olecranon, and the direction of the movement from before backwards. There is a distinct synovial membrane, though extremely thin, but capable of demonstration, especially at the postaxial side of the joint, where the greatest movement was found. There seem to be no distinct and separate ligaments, the place of the latter being supplied by the |
