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Show 1897.] MYOLOGY OF THE TERRESTRIAL CARNIVORA. 379 posterior third of the neck in Ursus mariilmus (45), in two specimens of U. americanus,(50, 52), in Procyon lotor (53), in four specimens of Lutra vulgaris (74, 75, 77, 79), and in Macalister's specimen of Viverra civetta (IX.), while in one specimen of Ursus americanus (49), in Nasua rufa (60), in Cercoleptes (61), in Ictonyx llbyca (70), and in Young's specimen of Viverra civetta (VIII.) they w^ere separate. In no animal belonging to the Felidae 1 have we found any fusion between the opposite sterno-mastoids, and the same applies to the Viverridae with the exception of one Civet (13), Genet (18), and Cryptoprocta. (10). In many animals, e. g. Procyon lotor (53), Ursus marltlmus (45), U. americanus (49), Lutra (74), and Herpestes (24), some of the dorsal fibres of the sterno-mastoid run forward and upward to join the contiguous cephalo-humeral. In Hycena striata (26, 27, 28), H. crocuta (29), and H. brunnea (30) tbe muscle is divided into an inner and an outer portion, the former going to the paramastoid process, the latter to the occipital ridge. This arrangement may therefore be taken as typical of the Hyaenidae, and it is interesting to notice that in Proteles (25) the same arrangement was found. Cleido-mastoid.-This muscle, as has already been pointed out, is usually distinct from the sterno-mastoid though it may be fused with it at its insertion. It rises from the rudimentary clavicle or, when that is absent, from the tendinous intersection in the cephalo-humeral muscle; it passes forwards to be inserted into the paroccipital process deep to the insertion of the sterno-mastoid. The spinal accessory (Xlth) nerve seems to have a most constant relation to this muscle, first piercing it and then running between it and the sterno-mastoid to the trapezius. In Cercoleptes (61) the nerve passed entirely between the two muscles, but this was the only exception with which we met. It is interesting to contrast the behaviour of the spinal accessory in the Carnivora and Rodentia (XLI.) : in the former it pierces the cleido-mastoid, in the latter it passes deep to that muscle. Sterno-hyoid, Sterno-thyroid, and Thyro-hyold.-Owing to the narrowness of the sternum, the two first-named muscles rise largely from the first rib. In Proteles, Watson (XIII.) describes tbe two sterno-hyoid muscles of opposite sides as being fused in the middle line, but this was not noticed in the Hyaenidae or indeed in any other animal. In Lutra cinerea, Macalister (XXXVII.) describes a tendinous intersection in both the sternohyoid and sterno-thyroid ; we found the same thing in the Dog (31), though in that animal the sterno-hyoid and thyroid were fused on the caudal side of the intersection. Devis's specimen of Viverra civetta (X.) seems to have shown a similar arrangement. In the other animals examined the muscles had the usual human attachments. Omo-hyoid.-When this muscle is present it has the usual 1 In F. catus (7) and F. leo (la) we cannot satisfy ourselves whether a fusion does or does not exist. 25* |