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Show 1897.] MYOLOGY OF THE TERRESTRIAL CARNIVORA. 385 nivora. In Herpestes griseus (24) some of the deeper fibres of the pectoral were continuous with the supraspinatus. Trapezius.-The first part of the trapezius (clavo-cucullaris of Straus-Durckheim) is continuous with the clavicular part of the deltoid, forming the cephalo-humeral muscle. It rises from the curved line of the occiput and from the ligamentum nuchae and is usually well developed in Carnivora, especially in the Hyaenidae. When it reaches the region of the rudimentary clavicle there is usually a tendinous intersection marking the line of demarcation between the trapezial and deltoid elements of the muscle; at this point it is usually joined by a part or the whole of the cleido-mastoid muscle. In some cases, e. g. Procyon lotor (53) and Lutra vulgaris (74), the clavicle is fairly developed, and in these only a few fibres are attached to the bone which lies deep to the aforesaid tendinous intersection'. Besides the union with the cleido-mastoid at the intersection, slips are often given to or received from the sterno-mastoid; this is most marked in Lutra (74), in which the two muscles are largely fused, and also in Ictonyx (70). The second part of the trapezius (acromio-cucullaris) is very constant; it rises from the ligamentum nuchae and anterior thoracic spines and is inserted into the anterior lip of the spine of the scapula. At its insertion it is in close contact with the acromio-trachelian, and in Vlverrlcula malaccensis (15) and to a less extent in Canis familiaris (31) the two muscles are fused here. In Ictonyx zorilla (69), /. lyhica (70), Nasua (58), and Cercoleptes (61, 62) the posterior part of the origin of the acromio-cucullaris has no attachment to the thoracic spines, but is united to the muscle of the opposite side by a tendinous junction. The third part of the trapezius (dorso-cucullaris) rises from the posterior thoracic spines and is inserted into the base of the spine of the scapula. In Cyncelurus (9) the second part, according to Ross, rose from the ligamentum nuchae and 7th cervical spine, while the third part came from the anterior six thoracic spines. In some cases-e.g. Genetta vulgaris (18), G. tigrina (16 a), Hycena striata (26), Procyon lotor (53), Gallctls vittata (63), Ictonyx zorilla (69), /. lyhica (70), and Lutra vulgaris (74)-the third is separated from the second part by a fibrous interval: in other cases the two parts are in close contact: though the arrangement does not seem to depend in any way on the relationship of the various animals, since Procyon lotor (53) has a separation, while in P. cancrlvorus (57) the two parts are continuous. It m a y be noticed that in all Carnivora the second and third parts of the trapezius are feebly developed in comparison wdth the first; this is true even of the Hyaenidae, in which the neck and shoulder muscles are so very powerful. Latissimus dorsi.-The latissimus dorsi rises from a large number 1 The development of the clavicle seems to vary a good deal individually; we found it well marked in Lutra vulgaris, but Macalister did not notice it in Lutra cinerea. Perrin (XXIX.) found it in Cercoleptes, but in our specimen there was no trace. Pos?ibly age is tbe explanation. |
