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Show "^•J ANATOMY OF ORNITHORHYNCHUS. 705 between the longus and the magnus. It receives a fine the obturator nerve. Fig. 4. M U S C L E S OF THIGH. o' [ Gracilis reflected. y. Adductor mass. 1. Upper one, going to femur, is longus. 2. Middle, slender one is brevis. 3. Lowest, going to tibia, is magnus. S. Is a small portion of semi-membranosus seen from the front. e. Sartorius cut through. Adductor magnus.-Is a thick muscle which has a comparatively narrow origin from the inferior surface of ramus of ischium, its origin extending as far back as tuberosity. It is inserted by its base into the upper third of tibia. It may be separated into two parts, anterior and posterior. Each part receives a branch from the obturator nerve. The anterior portion receives in addition a branch from great sciatic, which enters it on its superior surface. The nerve supplies three muscles, adductor magnus, semimembranosus, and two slender branches to supposed inferior gemellus. In Echidna, this muscle is inserted into linea aspera, in common with brevis (Mivart, loc. cit.). The muscle Coues describes as adductor magnus is inserted into thigh-bone. He homologizes it by its insertion into femur. Its nerve-supply, however, together Avith the fact that in many mammals adductor magnus is inserted into tibia, lead me to think that the one described above is true adductor magnus. PROC. ZOOL. Soc-1894, No. XLVII. 47 |