I 



THE EXTREMITIES OF ORYCTEROPUS CAPENSIS. . r »83 



middle of the distal margin of the bone, and is here bridged over by a distinct* but very 

 delicate ligament, which is attached to the above 4 tubercle. Near its termination the 

 tendon broadens, and, crossing over that of the extensor carpi ulnaru, is inserted, partlj 

 into the base of the proximal phalanx of the fifth digit, partly into a sesamoid ossicle 



situated at the ulnar side of this phalanx, and partly, but principally, into the ulnar side 

 of the distal phalanx of the same digit. 



I did not find any offset to the fourth digit, as described by Prof. Humphry 1 , and 

 represented by Cuvier in one of his figures 2 as the principal branch of the extensor minimi 



digit i. 



Such an offset has, however, been found by Church in the Orang 3 ; and Henle, more- 

 over, describes'' the tendon as sometimes splitting in Man, the two divisions either passing 

 separately to the fourth and fifth digits, or both terminating at the latter digit, aa happens, 



according to Meckel, in the Ormihorhynchus 1 \ 



In Jlyrax Capcnsis this muscle was found by Dr. Murie and Mr. Mivart dividing early 

 into two slips, which terminated separately at the fourth and fifth digits. 



In Dasyprocta cristata, according to the same authorities, the tendon :ilone was split, 

 but its branches had a similar termination 6 . 



Extensor carpi ulnaris.— Starts from tlu^ external condyle of the humerus, immediately 

 below the preceding muscle, and for the first half of its course is intimately fused with it. 

 On reaching the distal extremity of the ulna, it becomes tendinous, the strong flat tendon 

 lying to the ulnar side of the tuberosity mentioned in the description of the preceding 

 muscle. Its tendon divides into two branches, one of which is inserted into the ulnar 

 side of the base of the metacarpal of the fourth digit, the other into the inferior face of 



the like factor of the fifth. 



The former of these branches has been well represented by Cuvier 7 . 



In the Anteater, according to Meckel 3 , this muscle goes to the rudiments of the fourth 



and fifth digits. 



Flexor carpi ulnaris— This muscle may be described as made up of two factors : — a 

 small, or deep, portion, which arises by a very distinct rounded tendon from the middle 

 of the inner edge of the ulna; this tendon, running between the flexor profundus and the 

 more superficial factor of the flexor ulnaris, after gradually widening, becomes muscular 

 at about the distal fourth of the bone ; and the muscle, also gradually widening, is finally 

 inserted all along the stem of the long, style-shaped os pisiforme 9 : the bulk of the 

 muscle arises from the whole inner edge of the ulna, and from the olecranon, by a broad 

 aponeurotic tendon, to which the flexor prqj undus is closely adherent. Muscular fibres 

 are not added to this aponeurosis until it attains the middle of the forearm. At its ter- 

 mination this factor has two distinct insertions— the outer into the free extremity of the 



i LMm b& p. 308. 2 PL 254. fig. 2. s Nat Hist. Rev. No. 4, Oct. 1861, p. 514. 



Muakellehre, p. 207. 

 Proc. Zool. Soc. April 



Op. cit. pi. 254. fig. 



« Le pisiforme est tres-singulier, il ressemble a un 



8 Vergleieh. Anat. iii" Theil, p. 549. 



Op 



p. 135.) 



VOL. XXVI 



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