MR. J. C. GALTON ON DASYPUS SEXCINC TUS. 



fibres are fused. It then passes obliquely, but gradually, to* ardi the middle Lino of 

 forearm, and, upon passing on to the dorsum of the fore foot, is bridged over bv a si I 

 ligament, which crosses from the terminal crest of the median dorsal ridse of the ra« 



5 IS 



-— s 



to the cuneiform bone. Next, it becomes tendinous, dividing into two broad tendons, 

 which divide dichotomously at the metacarpophalangeal articulation, and proceed as 

 follows :—The outer division of the radial tendon passes to the index ; the ulnar division 

 of the same tendon, after being joined by the radial division of the ulnar tendon, to tin- 

 middle digit; while the ulnar division of the latter tendon passes to the fourth (annu- 

 laris) digit. Each of the divisions of these tendons passes to the root of the ungual 

 phalanx of the digit to which it belongs. 



This muscle, according to Meckel 1 , passes in Dasypus only to the second, third, and 

 fourth fingers — the arrangement, in fact, with the exception of the intercommunication 

 of the three tendons, which I have just described. 



Extensor annularis. — Immediately below the former muscle arises, from the strong 



supracondyloid ridge of the humerus, and from a strong tendinous septum which is 

 attached to the median dorsal ridge of the ulna, a small, fusiform muscle, which does not 

 become tendinous till when a little in advance of the extensor communis, after running 

 parallel with it in the forearm. 



Its tendon divides, almost immediately, into two slips, the radial of which passes to 

 the base of the proximal phalanx of the fourth finger, while the ulnar slip is inserted 

 into the base of the ungual phalanx of the little finger. 



Extensor minimi digiti. — Having an origin similar to, but lower than, that of the la-t- 

 described muscle, and fusing with the same for some little distance, passes a shorter and 

 flatter muscle, parallel with the above, to be inserted into the dorsal aspect of the 

 metacarpal bone or proximal phalanx of the little digit, by a tendon which has a com- 

 paratively wide expansion at its termination, and a greater length than that of tin- 

 preceding muscle. 



Cuvier, in one of his plates of the myology of Dasypus, represents the last two muscles 

 as I have described and figured them; but the extensor communis has, according to 

 his representation, but a single primary tendon, which splits, however, into three 

 secondary divisions, passing to the index, middle, and fourth fingers. The delicate 

 offset from the extensor mdtek, destined for the pollex, is, moreover, not represented*. 

 Meckel states that the extensor minimi digiti passes only to the fourth digit m the 



"Tatu" 3 . .... • ♦• **i * 



n , . 7 muv w ,i,nip irisps from the inferior termination 01 the strong 



Extensor carpi ulnaris.— This muscle arises irom mc ^ 6 



« • , . i „ ,,, i „ iry,Tnefliatelv below, and fusing at its origin with, the 



" supinator rictee of the humerus, lmmeaiaieiy uwu , & © 



i . ., v w11 cnip olso from the strong ligamentous septum 



lowermost fibres of the preceding muscle, also noni me j «* r 



i . , , +™™iTi<if7nn of the median dorsal rul^e ol the ulna 



which is stretched from the spinous termination oi m «s 



.i * ^ «,„,«««+ or rido-e — and from the strong ndge which 

 across to the lower extremity of the supinator na D e— a -, 



, ■ ' , o +lip n ), nve bone; the muscle, which is at origin 

 runs alon<? the inner (or ulnar) edge of the above Done, ' » 



xuu b tuc miici V " / wwvriTC orqduallv up to its tendon, which appears to 



of a more or less triangular shape, narrows graauany up 



. i o-q £<* 9 3 Op. cit. p. 549. 



1 Op. cit. p. 548. J 0*. *- Pi- 2o9 « fi S' 2 - 



