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Show 996 MESSRS. B. C. A. WINDLE AND F. G. PARSONS ON [Dec. 19, specimen (6), the posterior muscle, instead of passing round the front of the leg as it did in our case, wrapped round the back of the thigh, and was inserted just below the insertion of the flexor cruris lateralis. Humphry (2) also found the muscle double, but Mackintosh does not seem to have noticed this condition in his specimen. In Cholcepus we have records of three specimens (8, 9, 10), all of which agree in calling the muscle double. Among the Mgrmecophagid.ee, Myrmecophaga (11) has a double muscle, the anterior part of which rises from the ramus of the pubes internal to the ilio-pectineal eminence, and is inserted into the upper two-thirds of the cnemial crest of the tibia. The posterior part rises from the symphysis and descending ramus of the pubes, and is inserted below the last, into the lower part of the cnemial crest and shaft of the tibia as low as the middle of the bone. In Tamandua (14) the muscle rises from the sub-pubic arch, and in section would appear V-shaped, with the apex of the V directed mesially and its concavity including the adductor mass. Though there is no actual line of fission along it, yet the apex of this V clearly is equivalent to the line of separation into anterior and posterior portions in Myrmecophaga. The wide and strong insertion of this muscle is into more than half of the inner side of the tibia. Rapp describes this muscle as very broad in his specimen (15). In Cyclothurus (17, 19, 20) the muscle is single and broad. Among the Dasypodidce the adductor cruris may be either single or double, the latter coudition obtaining as far as its insertion into the fascia of the leg from the knee to the ankle in our specimen (22). In another specimen (24) it was single. Galton (X.) describes it as a thin muscle in Dasypus (23), but Macalister (VII.) says that it is broad in Tatusia (25). Iu Chlamydophorus (27, 28 a) it is single and thin. In the Manidce the muscle may also be single or double. In two cases (32, 34) it fell under the former category, and in other two (29, 33) under the latter. In all cases the muscle is of specially large'size in this family. In the Orycteropodidce (35, 36, 37) the adductor cruris is single and broad. Semimembranosus.-In all the Edentates the semimembranosus is a very constant muscle rising from the tuber ischii and part of the ramus, and obtaining insertion into the upper part of the internal surface of the tibia, deep to the long internal lateral ligament. The tibial insertion is especially extensive in the Dasypodidce, and it is remarkable that in these animals the long internal lateral ligament is attached nearly as low as the middle of the tibia. Presemimembranosus.-By many observers this has not as vet been recognized as a separate muscle, some including it in the adductor mass, others describing it with the semimembranosus Haughtou calls it the adductor primus; Macalister, the adductor magnus condyloidea. In our specimens of Bradypus (1) and Cholcepus (8) it was a perfectly distinct muscle, rising from the tuber ischn, and being inserted into the femur just above the |