| OCR Text |
Show 332 MESSRS. B. C A. WINDLE AND F. G. PARSONS ON [Mar. 7, fascia of the Avrist. In three specimens of Cholcepus (8, 9, 10) the muscle was inserted into tbe scaphoid. In the Myrmecophagidce the insertion was into the second metacarpal in Myrmecophaga (11, 13), Tamandua (14), and Cyclothurus (17, 18), but in another specimen of Myrmecophaga it Avas into the third metacarpal. Among the Dasypodidce the insertion Avas into the trapezium in Dasypus (22, 23), but in Tatusia (25) and Chlamydophorus (27) into the first metacarpal bone. In the Manidce the insertion varies. In four specimens of Manis (29, 30, 31, 32) the muscle passed to the second metacarpal only, but in two others (32, 34) slips were given to the three radial metacarpals. In Oryeteropus (35, 36) the insertion was into the second metacarpal, but a sesamoid bone Avas apparently developed in the tendon, a portion of Avhich was attached to the styloid process of the radius. In 37 it was also inserted into the second metacarpal. Palmaris longus.-In six specimens of Bradypus (1, 2, 3, 4, 5, 6) this muscle was present, rising from the internal condyle and gaining an insertion into the palmar fascia by one or more of tbe bony prominences about the palm. In three specimens of Cholcepus (8, 9, 10) the muscle Avas also present. In the Myrmecophagidce it is difficult to determine what is palmaris longus and what flexor sublimis digitorum. A careful comparison of the descriptions given by Macalister (13) and Pouchet (12) with the College of Surgeons' specimen (11) makes us inclined to believe that in Myrmecophaga the palmaris longus is absent. In Tamandua (14, 16) the muscle extends from the internal condyle to the fibrocartilaginous anterior annular ligament. In Dasypus (22, 23) some superficial fibres of the flexor sublimis passed to the aunular ligament, representing, we think, a palmaris longus, but in another specimen (24) the muscle is absent. In Manis the muscle may extend from the condyle and olecranon process to the palmar fascia (29, 31, 33) or it may be fused Avith the flexor sublimis (30, 32, 34). In Oryeteropus the muscle is either fused Avith the flexor sublimis (35, 36) or is absent (37). Flexor sublimis digitorum.-In Bradypus this muscle is ahAavs absent (1, 2, 3, 4, 5, 6). In Cholcepus it is present and has tAvo delicate tendons (8, 9, 10), which are more or less connected above with the palmaris longus. In Myrmecophaga (11, 12, 13) and Tamandua (14, 15, 16) it rises from the internal condyle as well as the olecranon process and some of the shaft of the ulna beloAv it. It is inserted into the middle phalanx of the medius, splitting to enclose the flexor profundus tendon, but not showing the rino-which is so evident in Bodents, Insectivores, and Carnivores. In Dasyp>us the muscle gives tendons to the index and medius (23, 24) or to the medius only (22). In the Manidce the arrangement of this muscle is very inconstant and various Avriters seem to have confounded it with the palmaris longus. In the two specimens (29, 30) AA'hich Ave dissected the arrangement was quite different. In 32 there was a slip for the pollex from the fascia of the lower part of the forearm, condylar slips for the index and medius, Avhile |
