| OCR Text |
Show 334 MESSES. B. C A. WINDLE AND F. G. PARSONS ON [Mar. 7, tendon to the rudimentary pollex. Oryeteropus (35, 37) has condylo-ulnar and central parts, also radial and ulnar. The common tendon, which possesses no sesamoid, gives off four tendons. Lumbricales.-Amongst the Bradypodidce, Bradypus (1, 2, 3) is devoid of any of these muscles, but Cholcepus (9) has two, one for each digit. Li the Myrmecophagidce two specimens of Myrmecophaga (11, 12) had four muscles, whilst another (13) bad only two. Tamandua (14) bad three, that for the index being absent, but in another specimen (16) there were six. In Cyclothurus two specimens (18, 20) had two lumbricales, whilst another (17) had none at all. Dasypus (22, 23, 24) possessed none at all. In Chlamydophorus Hyrtl (28) failed to find any ; but in another specimen (27) seven slender fleshy bundles are described as rising from the sesamoid cartilage iu the flexor tendon, Avhich are inserted into each side of the middle phalanges of all the digits except the pollex. In Manis the number is very variable ; there AA*ere three in (30), four in (32) and (34), and two in (33). In all the specimens of Oryeteropus of which Ave have records (35, 36, 37) there were four. Pronator quadratus.-Amongst the Bradypodidce this muscle is very small, both in Bradypus (1, 2, 3, 5) and Cholcepus (8, 9, 10), occupying in the former only one-eighth to one-sixth of the forearm. The Myrmecophagidce, viz. Myrmecophaga (12,13), Tamandua (14), and Cyclothurus (17, 18, 20), have the muscle extending over the Avhole length of the interosseous space. In Myrmecophaga (12), Pouchet notices that the lower third of the muscle corresponds to the human pronator quadratus in being attached to the surfaces of the radius and ulna, whilst the upper two-thirds is attached only to the opposed margins of the bones. In the Dasy-podidce and Manidce the muscle is usually absent, this being tbe case in Dasypus (22, 23), Chlamydophorus (28), and Manis (29, 30, 31, 32, 33, 34). In Tatusia (25, 26) it Avas extremely rudimentary, and in one specimen of Chlamydophorus (27) it Avas represented by a feeble fibrous cord. In Oryeteropus (35) it occupied the Avhole length of the bones, as was the case in the Myrmecophagidce, though Humphry describes it as beiug small. Supinator longus.-This muscle is always present in the Bradypodidce and is often double. Of four specimens of Bradypus, three (2, 4, 5) had the muscle delaminated into a superficial and a deep layer, both of Avhich arose from the supracondylar ridge, the more superficial being inserted lower down than its deeper felloAv. In the other three specimens (1, 3, 6) the muscle was single and rose from the loAver half of the humerus. In the last of these (6) the supinator longus and pronator radii teres joiued before their insertion. The bilaminar condition of the supinator longus Avas found in all three specimens of Cholceqms of Avhich we bavTe records (8, 9, 10). In 9 the superficial layer was inserted into the fascia over the Avrist, the deep into the radius. In the other specimens (8, 10) both parts Avere attached to the radius. In the Myrmeco- |
