1900.] MR. F. E. BEDDARD OX BASSARICYON ALLENI. 669 



Parsons in their account of the muscular anatomy of the Carnivora 

 in general \ 



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 & Parsous'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 f 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 the 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 rhom- 

 boideus anterior or rhomboideus capitis. 



There is no trace that 1 could discover of any Rhomboideus 

 profundus such as occurs in many Arctoids (especially Mustelidae), 

 and even in the near ally of the present genus, Cercoleptes. 



The Serratus magnus forms one muscle including the levator 

 anguli scapula?. Its origin extends as far back as the 7th rib. Its 

 attachment to the scapula is almost exactly coextensive with 

 that of the Ehomboid. There is a tendency to a slight differentia- 

 tion 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 Bassaricyon 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 dor-si. — 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. II., 1898, p. 152. 



2 For the muscular anatomy of that animal see Perrin, P. Z. S. 1871, 

 p. 547. 



Proc. Zool. Soo.— 1900, No. XLIV. II 



