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Show 1899.] THE MYOLOGY OF THE EDENTATA. 337 index as well. In Dasypus (22, 23) there are tendons for the index and pollex, but in (24) for the index only. Iu Tatusia there are tendons for the index and medius in (25) and for index only in (26). In Chlamydophorus (27) the tendon to the index gives a fascial slip to the pollex. In Manis (29, 32, 33) the extensor indicis alone is present, but in one case (30) there is a polliceal slip as well. Oryeteropus has a well-developed extensor profundus, wbich in two cases (35, 36) went to the index, medius, and annularis, and in another (37) to the index and medius only. It is interesting to notice that whilst in some of these animals the origin is as usual from the dorsal surface of the ulna, in others it seems to have slipped clown and the muscle rises from the dorsum of the carpus and closely corresponds to the extensor brevis digitorum pedis. This low origin was found in the following animals : Bradypus (1, 4, 5), Choloepus (10), Cyclothurus (17), Manis (30, 33). Palmaris brevis.-This muscle was well marked in Bradypus (1), Tamandua (14), and Cyclothurus (18). In Tamandua it was a peculiarly large muscle, filling the great boxing-glove like pad on the ulnar side of the hand. In Myrmecophaga it was very feeble, if, indeed, it was present at all, whilst we failed to find any trace of it in any other Edentate. Supinator brevis.-In the Bradypodidce this muscle covers the upper third of the radius. In two specimens of Cholcepus (8, 10) it was divided into two layers, between which lay the posterior interosseous nerve, but in another specimen of the same animal (9) this division was not noticed. In the Myrmecophagidce the muscle is inserted into the lower part of the radius-Myrmecophaga (11, 12), Tamandua (14), and Cyclothurus (17,18,19, 20). Among the Dasypodidce the muscle is small in Dasypus (22, 23), small or absent in Tatusia (25, 26) and Chlamydophorus (27, 28). In the Manidce,, on the other hand, it is inserted into nearly the whole length of the radius (29, 31, 32, 33, 34), and has a sesamoid bone developed in its origin. In Oryeteropus (35, 36) the muscle only occupies the upper half of the radius. Lntrinsic Muscles of the Hand.-We find it extremely difficult, in reading the literature of the subject, to understand at what depth the various muscles were placed and to which digit precisely they were attached. As it has been always our desire to err less on the side of commission than of omission, we feel bound to omit much which did not appear clear to us, and must therefore confess that our account of these muscles in the Edentata is somewhat of the scantiest. In Bradypus (1) there was an adductor pollicis and also adductors of the index and annularis, which were superficial to the deep branch of the ulnar nerve. An interosseous muscle is present between each of the metacarpal bones. In Cholcepus (8) there is an adductor indicis, belonging to the first layer of deep muscles, which rose from the carpus and was inserted into the ulnar side of the base of the proximal phalanx of tbe index; there is also an interosseous muscle on eac'n side of the index. In the |
