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Show 1899.] THE MYOLOGY OF THE EDENTATA. 1007 three lumbricales are usually found, while in the Orycteropodidce (35, 36) there are four. Musculi breves pedis.--The abductores hallucis et minimi digiti are of course absent in the Bradypodidce, but in all the other families they are present. In the Orycteropodidce, however, the abductor hallucis is replaced by fibrous tissue. The flexor brevis hallucis is present in all Edentates except the Bradypodidce. In the Orycteropodidce (35, 36) its absence is noted, but Humphry (36) states that it is replaced by fibrous tissue. It is present in all other Edentata, including Cyclothurus. The abductor minimi digiti is present in the Myrmecophagidce, Dasypodidce, Manidce, and Orycteropodidce; it usually rises from the base of the fifth metatarsal bone, instead of from the calcaneum as in most mammals. The superficial layer of deep muscles, i. e. those which lie superficial to the deep branch of the external plantar nerve and are usually called adductors, are wanting in the Bradypodidce and Manidce. In the following animals adductores hallucis et minimi digiti were found :-Cyclothurus (20), Dasypus (22), Tatusia (25), and Oryeteropus (35, 36). Tamandua (14) in addition had an adductor indicis. The interossei are usually present as paired flexores breve3, but in the Dasypodidce and Manidce a differentiation into dorsal and plantar groups is noticed; their exact arrangement, however, differs in different specimens of the same animal. Abdominal Muscles. Serratus dorsalis (S. posticus).-The two portions of this muscle, thoracis and lumbalis, seem to be but little developed in the Edentata, and this statement particularly applies to the former of the two. Amongst the Bradypodidce the muscle is represented only by a fibrous sheet in Bradypus (1), whilst in Cholcepus (10) the thoracic portion is absent, but the lumbar, attached to the lower ribs, is present. Amongst the Myrmecophagidce a fibrous representative of the muscle was found in Tamandua (14); it is not figured, however, in Cuvier and Laurillard's plate of the same species (16). Dasypus amongst the Dasypodidce does not seem usually to possess any representative of this muscle, for none was found in (22); Galton (23) does not mention one, nor is any figured by Cuvier and Laurillard (24). Indeed we could have asserted that there is none but for the fact that Macalister (VI.) seems to have found a representative of the muscle in one case. In Tatusia (25) a very feeble thoracis was found, and a lumbalis attached to the lower four ribs. Chlamydophorus (27, 28) had a similarly arranged lumbalis but no thoracis. In Manis (29) a fibrous representative was alone found. In Oryeteropus (37) Cuvier and Laurillard figure a continuous sheet extending from the third to the tenth dorsal vertebra which appears to be an unusually well-developed thoracis. Rectus ventralis.-This muscle in the majority of forms reaches as high a point of attachment as the first rib, though sometimes 65* |