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Show 1897.] MYOLOGY OF THE TERRESTRIAL CARNIVORA. 377 paroccipital process and often from the contiguous paramastoid and bulla tympani; it is inserted into the body of the lower jaw midway between tbe angle and symphysis (see fig. 4, p. 378). It has no connexion with the hyoid bone, and the only evidence of a separation into two bellies is a feeble line of tendon about the middle, which is quite superficial and does not extend into the interior of the muscle. In some cases, e.g. Civetta (12), Genetta (18), Ursus (52), Nasua (60), and Ictonyx (70), no tendinous intersection ac all was noticed. In spite of its appearance the anterior part of the muscle is supplied by the mylo-hyoid, and the posterior by the facial nerve. Mylo-hyoid.-The mylo-hyoid has the same attachments as in M a n (see fig. 4, p. 378). It usually extends as far forwards as the symphysis menti, but in Canis (31), Hyaena striata (28), aud H. crocuta (29) it ends anteriorly in an angle, the convexity of which is towards, but does not reach the symphysis. In Procyon lotor (53) the arrangement is the same as in the Canidae and Hyaenidse, but Nasua rufa (60) agrees with the rest of the Carnivora in this respect. Genlo-hyoid and Genio-hyoglossus.-Nothing remarkable was noticed about these muscles. They have the usual human attachments. Stylo-hyoid.-The typical carnivorous stylo-hyoid seems to consist of two parts, superficial and deep: the former is a small slip which rises from near the root of the paroccipital process and passes over the digastric, to reach the hyoid bone; the latter rises deep to the origin of the digastric and is usually inserted into the epihyal element of the hyoid arch, it is sometimes spoken of as the masto-hyoid (see fig. 4, p. 378). This arrangement was noticed in F. catus (7), Genetta (17, 18), Herpestes (24), Cryptoprocta (10), Canis (39), and Cercoleptes (61). In the Mustelidae the superficial part was not seen, but unless looked for it may easily escape notice, and this is also the case with the deep part. It is possible that the human arrangement of the stylo-hyoid, in which the digastric tendon passes through it, m ay be explained by looking upon the human muscle as a combination of the stylohyoid and masto-hyoid of the Carnivora. Styloglossus.-This is always present and is by far the best developed of all the styloid muscles in Carnivora ; it rises from the stylo- or epi-hyal elements of the hyoid arch, and passes to the superficial side of the hyoglossus as in M a n (see fig. 4, p. 378). Ceratodiyold.-This muscle is described by Straus-Durckheim in the Cat (II.) and by Alix in the Polecat ( X X X . ) ; it passes from the thyro-hyal to the cerato-hyal elements of the hyoid apparatus. W e have failed to notice it in any of the animals which we have dissected, while in Genetta (18) and Herpestes (24) we specially looked for it without success. Stylo-pharyngeus.-The stylo-pharyngeus is always present though small; it rises from the deep surface of the stylo-hyal and passes to the pharynx. PEOC. ZOOL. SOC-1897, No. XXV. 25 |
