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Show 1899.] THE MYOLOGY OF TnE EDENTATA. 995 femur just above the internal condyle. The rest of the mass came from the sub-pubic arch and was inserted into the middle third of the femur. The other two specimens of which we have records (2, 5) were dissected at a time when the presemimembranosus was as yet unrecognized as a separate muscle, and we suspect that the description of this muscle is included in that of the adductors. It is worth noting that the pectineus and adductors rise as near the middle line of the body as they can, and wrap well round the back of the femur so as to act powerfully as external rotators. In Cholcepus (8), when the presemimembranosus is kept separate, the adductors closely agree with those of Bradypus* Among the Myrmecophagidce, Myrmecophaga has the mass divided into tv.0 planes, the more superficial of which rises from the horizontal ramus and anterior half of the symphysis of the pubes and is inserted into the lower half of the femur. This part is pierced by the branch of the obturator nerve to the posterior adductor cruris (gracilis), and possibly, therefore, corresponds to the human adductores longus et brevis. The more posterior part of the mass has the same origin as the last, but lies deep to it and obtains origin from rather more of the symphysis ; it is inserted into the lower two-thirds of the femur, and probably corresponds to the human adductor magnus. The whole of the adductor mass is supplied by the obturator nerve. In Tamandua (14) two layers can also be made out, both inserted below the middle of the femur. Rapp (15) says of this animal that the adductors cannot be divided into three layers. In Cyclothurus, Humphry (17), Meckel (19), and Galton (20) were all able to distinguish three layers, but possibly one of these was the presemimembranosus. The Dasgpodidce (Dasypus 22, 23, Tatusia 25, and Chlamydophorus 27,28, 2ba), all present an indivisible adductor mass. In the Manidce we were able to make out three distinct parts, viz., (a) to the outer border of the femur above the condyles under cover of the outer head of the gastrocnemius (which reaches unusually high up), this is probably adductor longus ; (b) to the middle third of the femur (adductor brevis); and (c) the most posterior (adductor magnus) to the lower part of the femur. In other specimens (32, 33, 34) the dissectors all agree that three layers can be seen. In the Orycteropjodidce (35, '66) three layers are also described. Adductor cruris (Gracilis).- The Bradypodidce seem remarkable for the constant presence of a double adductor cruris, but the insertion differs from that which one is accustomed to associate with the double condition of that muscle amongst the Mammalia. In our specimen of Bradypus (1) the anterior adductor cruris rose from the inner part of Poupart's ligament, and was inserted into the upper part of the inner surface of the tibia. The posterior rose from the symphysis pubis, and, after reaching the knee, passed in front of the shaft of the tibia to be inserted into the fascia on the outer side of the leg below, and continuous with the insertion of the flexor cruris lateralis (biceps). Both parts were supplied by the obturator nerve. In Cuvier and Laurillard's |