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Show 1897.] MYOLOGY OF THE TERRESTRIAL CARNIVORA. 387 capitis; consequently when they state that this is absent the muscle may still rise from the whole length of the ligamentum nuchae. Among the Felidae the rhomboideus anterior is always present; this is the case in F. leo (1 a), F. tigris (3), F. pardus (4), F. catus (6), and Cgncelurus (9). The Viverridae are remarkable for the frequence with which the rhomboid sheet fails to reach the skull, due probably to the great distance which there is between the head and the shoulder-blades in many of these animals. In Crgpto-procta (10), Viverra civetta (12, 13, 14), Vlverrlcula malaccensis (15), Genetta tigrina (16), Genetta vulgaris (18), aud Paradoxurus tgpus(19) the rhomdoideus anterior never reached further forward than the level of the spine of the axis ; another specimen of Paradoxurus (20) showed a fascial continuation of the muscle up to the occiput, while in Herpestes nepalensis (23) and Herpestes griseus (24) a definite occipital origin was noticed. Proteles (25) has no occipital origin for its rhomboids. Among the Hyaenidae the occipital origin was found in H. striata by Meckel (27), but not by Young (26) or Cuvier (28); it is also wanting in H. crocuta (29). In the Canidae there is an occipital origin in Canis familiaris (31, 32, 33, 37, 39) and C. aureus (41). Among the Ursidae the rhomboideus anterior is well developed and comes from the skull in U. maritimus (45), in two specimens of U. americanus (48, 52), and in U. arctos (47). In two other specimens of U. americanus (49, 50) the occipital portion was absent. Among the Procyonidae the occipital origin is well marked and the whole muscle forms one continuous sheet in Procyon (53, 54, 55, 56, 57), Nasua (58, 60, X X X I X . ) , and Cercoleptes (61). In the Mustelidae the portion of the rhomboid which rises from the occiput is always present and usually is a separate slip (see fig. 5, p. 381) ; this is the case in Galictis vittata (63), Gallctls barbara (64), Mustela putorlus (65), Mustela folna (66, 67), Ictonyx zorilla (69), Ictonyx lyhica (70), Meles taxus (71, 72, 73), Lutra vulgaris (74, 79), and Lutra cinerea (78). It is interesting to note that these Mustelidae in which the gap between the occipital aud cervical portions of the rhomboid sheet is so constant are equally remarkable for the constant presence of the rhomboideus profundus muscle. This muscle, as has. already been stated, is fused with the rhomboid at its insertion, and by many authors is described as part of the rhomboid. W e cannot help throwing out the suggestion, though we have no direct proof, that the gap in these animals between the occipital and nuchal portions of the muscle is caused by a sinking down of some of the fibres to acquire a new origin from the transverse process of the atlas, so that the rhomboideus profundus is a displaced portion of the rhomboid sheet. To sum up, the rhomboid always seems to have an occipital origin iu Ihe Felidae, Canidae, Procyonidae, and Mustelidae. In the Yiverridae and Hyaenidae the occipital origin is the exception. |