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Show 1900.] MR. F. E. BEDDARD ON BASSARICYON ALLENI. 669 Parsons in their account of the muscular anatomy of the Carnivora in geueral \ I have therefore thought it desirable to dissect at least the more important muscles of Bassaricyon, with a view of testing some of the classificatory conclusions of the two authors just named. This task has been rendered easier by the very useful summary of muscular characters in various families of Carnivora with which Messrs. Windle & Parsons's memoir concludes. The Pectoralis consists, as in the Kinkajou 2, of three distinct portions. The anterior, and at the same time the most superficial part of the muscle, is the smallest division. It is about | inch in breadth at its origin from the sternum, and narrows gradually towards the insertion. Beneath this, and extending from the anterior to very nearly tbe posterior extremity of the sternum, is a large sheet of muscle which forms the rest of the pectoralis. Anteriorly to behind the end of the first third of the sternum, this sheet of muscle is divisible into a superficial and a deeper layer ; behind this point there is an oblique tendinous inscription and the two layers are fused. They are inserted perfectly separately on to the humerus. The origin is not only from the sternum but also from the adjacent parts of the ribs. The Rhomboideus is entirely a single muscle ; the anterior part which arises from the head cannot be distinguished as a rhomboideus anterior or rhomboideus capitis. There is no trace that 1 could discover of any Rhomboideus profundus such as occurs in many Arcfoids (especially Mustelidae), and even in the near ally of the present genus, Cercoleptes. The Serratus mctgnus forms one muscle including the levator anguli scapulae. Its origin extends as far back as the 7th rib. Its attachment to the scapula is almost exactly coextensive with that of the Bhomboid. There is a tendency to a slight differentiation of the posterior muscle in that the insertion is faintly to be distinguished from that of the rest of the muscle. The Biceps, as is the case with the majority of the Carnivora, is a single-headed muscle possessing only the long head. It is curious that in this feature Bassaricgon departs from its nearest-allies ; for in Cercoleptes and in some other Arctoids the second head of the biceps is present. In Bassaricyon there was an obvious though small fleshy coracobrachialis, but no trace of a second biceps head. The Coracobrachialis has just been referred to. There was only one muscle present. Perrin reports its double character in Cercoleptes ; but Windle & Parsons found it to be single in that Carnivore. Latissimus dorsi.-This very large muscle is partly covered by the musculo-cutaneous, which latter is inserted into the humerus near 1 " The Myology of the Terrestrial Carnivora," Pt. I., P. Z. S. 1897, p. 370 ; Pt. IL, 1898, p. 152. 2 For the muscular anatomy of that animal see Perrin, P. Z. S. 1871, p. 547. PROC. ZOOL. Soc-1900, No. XLIV. 41 |