OCR Text |
Show 1885.] MYOLOGY OF THE WATER-OPOSSUM. 19 Fig. 6. cue JP.Qr.Z). G.A\ - T.P. F.Z.P. Sm. Myology of Water-Opossum. Q.E., quadriceps extensor; T.A., tibialis anticus; E.L.D., extensor longus E.L.P., extensor longus poliicis; P.L., peroneus longus; P.B., peroneus brevis ; P. T.D., peroneus tertii digiti; P.Qr.D., peroneus quarti digiti; G.E., gastrocnemius externus; PI., plantaris; T.P., tibialis posticus; F.L.P., flexor longus poliicis; Sm., semimembranosus; Pop., popliteus ; F.L.D., flexor longus digitorum ; G., gracilis ; St., semitendinosus. Muscles of Head and Neck. Masseter.-Enormously developed. Can be easily separated into several strata. The most superficial fibres arise from the strong masseteric fascia, and, passing inwards and backwards, are inserted into incurved portion of lower jaw. The next fibres, which also pass backwards, arise from krwer border of zygoma, and are inserted into a ridge, extending from condyle of lower jaw along lower border of outer surface. The most internal part arises from lower border and inner surface of zygoma, and its fibres, passing downwards and slightly forwards for the most part (the most anterior fibres passing slightly backwards), are inserted into outer surface of ramus between oblique line and dental foramen. The most posterior fibres of the superficial portion of the muscle are inserted into a tendinous raphe behind the ramus, which receives the most posterior fibres of internal pterygoid on its inner surface. Temporal.-Consists of two easily separable laminae. Superficial portion, thin in its posterior two thirds, arises from posterior part of inner surface of zygoma inseparable from masseter, and from a small portion of upper border of zygoma at its posterior 2* |