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Show 454 MR. ST. GEORGE MIVART ON THE [Juiie24, The two appear to form but one, which arises in part (as has been said) from the dorsum of the pterygoid. Superficial muscles of right side of head and of anterior part of trunk. CHE. Cerato-hyoideus externus. DA. First part of digastric. L. A. Leva-tores arcuum. L.A.I. Most anterior part of the same. M. Masseter. T. Temporalis. The masseter* (figs. 1, 2, & 3, M) is an exceedingly thick muscle, which is more or less divisible into a larger outer portion and a smaller inner part, the fibres being inserted into the tendon (which appears towards the lower part of the muscle) in a somewhat pen-niform manner. The muscle arises (between the temporal and digastric) from the antero-superior surface of the suspensorium, and is implanted, by its tendon, into the outer side of the mandible towards its upper border and in front of the insertion of the tendon of the temporalis. The digastricf (figs. 1, 2, & 3, D. 1 & D. 2) is also a considerable muscular mass, and springs from different origins; it is inserted by a strong tendon into the posterior extremity of the mandibular ramus. This strong tendon also connects the dorsal end of the hyoidean cornu with the posterior extremity of the mandible. The muscle appears to me to consist of two parts. One of these springs from the outer surface of the suspensorium, the origin ex- * Fischer, 'Anatomische Abhandlungen iiber die Perennibranchiaten und Ferotremen' (Hamburgh, 1864)^p. 59, tab. iii. B. m. t Fischer, 1. c. p. 50, tab. iii. B. dg". |