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Show 318 DR. GADOW ON THE ANATOMY OF PTEROCLES. [Mar. 21, adjoining part of the pubis. It is inserted by means of a very strong tendon into the externo-posterior plane of the outer trochanter. Another muscle, which we may call an accessory muscle to the m. obturator, is very small, and arises from the most proximal and lateral part of the ossa pubis et ischii near the acetabulum ; its fleshy but short belly is separated from that of the m. ischio-femoralis by the tendon of the main obturator muscle. It is inserted just between the tendons of these two muscles. As this small muscle is not supplied by tbe pl. ischiadicus, but together with the m. obturator, we cannot consider it to be a representative of the gemelli muscles, nor of part of the m. obturator internus of mammals. But the m. obturator of birds, together with its accessory muscles, might correspond to the m. obturator externus of Mammalian anatomy. The m. pubi-ischio-femoralis (m. adductor) consists of two layers, a lateral and more proximal and a median or distal one. The lateral part is ribbon-shaped, and arises from the latero-ventral margin of the middle third of the spines, opposite the pubis. It is covered laterally by the m. caud. ilio-femoralis, and is inserted into the hinder aspect of the distal half of the femur, lying mesiad from the femoral portion of the m. cauda? ilio-flexorius (femoral portion=" accessory part"). Tbe inner layer arises from the lateral margin of the distal two thirds of the ischium, but not from the os pubis or the ischio-pubic membrane. This flat muscle forms scarcely any tendon, and is inserted as a broad, but flat and vertical sheet into the distal half of the femur, including the internal condyle, and into the hinder surface of the head of the tibia. The m. popliteus is developed as usual. The m. tibialis anticus consists of two heads. The external or femoral is represented simply by a long tendon arising from the anterior inner margin of the internal condyle; its short belly soon fuses completely with the tibial or chief head, which latter takes its fleshy origin from the crest and head of the tibia. The strong tendon of this muscle passes under the transverse ligament of the leg, and is inserted into the anterior or dorsal sulcus of the tarso-metatarsal bone, not far from the joint. The whole muscle is covered superficially by the m. gastrocnemius (inner head) and by the m. peroneus superficialis. Nerve-supply, as in all the following muscles, from the ischiadic nerve. M. peroneus superficialis.-The most superficial muscle on the anterior and outer side of the leg. It arises from the crest of the head and from the anterior plane of the neck of the tibia, and sometimes from the head of the fibula. Its broad tendon passes round the outer side of the leg to the hinder aspect of the intertarsal joint, and then divides into two tendons: one is very broad, and forms the deep sheet of the susceptaculum ; the other one is much narrower, passes laterally over the external malleolus of the tibia, and then joins the tendon of the m. flexor perforatus dig. in. A m. peroneus profundus was not present in m y specimen of Pterocles. However, this muscle is subject to much variation. I found it well developed in Euplocamus pralata, but wanting in Gallus |