.-,28 MR. J. C. GALTON ON DASYPUS SEXCINCTUS. 



inserted, in company with the above prolongation, along the whole length of the manu- 

 brium in the middle line. This last-described element of the muscle, by overlapping 

 that portion of the pcctoralis which takes origin from the manubrium, and those fibres 

 of the stemo-mastoid which terminate along the upper edge of this sternal factor, aids in 

 the format ion of a kind of muscular sac, having the concavity looking outwards. 



Meckel describes the sterno- as distinct from cleido -mastoid in Dasypus ; and states 

 i hat both these factors of the compound muscle, especially the first, are of great thick- 

 oe8S. The stemo-mastoid, according to him, is attached along the whole of the first 

 third of the sternum. This muscle is also double in the Ant eater ; but the sterno- 

 mastoid in the Ai has this peculiarity, that at its upper part it splits into two pointed 

 heads (Zipfel), between which lies the styliform process 1 . 



The stemo-cleido-mastoid is clearly represented by Cuvier in one of his plates 2 . 



This muscle, in Dasypns sexcinctus, has no relation whatever, either of contiguity or 

 continuity, with the terminal portion of the rectus abdominis*. 



Snbclocius. — A very stout fleshy muscle. It arises from the irregularly oval and 

 roughish depression seen at the expanded anterior termination of the first rib, also from 

 it- superior edge, for a short distance. It then passes obliquely outwards over the 



and nerves, and, dipping beneath the clavicular portion of the deltoid 



with which it makes exactly a right angle at the point of crossing, passes to its insertion 

 It is inserted by a flat tendon along the whole extent of the upper ridge of the Ion 



icromion process of the scapula, and becomes, moreover, continuous with the strong 



fascia which covers the head of the humerus, and which is also lost over the supra- 



\pmatu9. The strong coraco-clavicular ligament passes across through the substance of 



the muscle, close to the insertion of the latter, splitting it into two unequal portions, the 



small r and anterior of which dips under the ligament to join its tendon, while the largest 



portion, comprising about two-thirds of the muscle in this part of its course, passes over 

 the ligament. 



Meckel makes no mention of the presence or absence of this muscle in Dasypus. 



lhe smaller factor of a muscle in Dasyprocta cristata, termed by Mr. Mivart and 

 Dr. Mune, in their paper on this Rodent 4 , sterno-scapular, has great resemblance to the 

 muscle in Dasypus which I have called subclavius. This factor of the stemo-scapular, 



which may be the subclavius, as the above authors, following Meckel 6 , suggest, 



" from the outer side of the base of the manubrium and from the cartilage of the first 

 rib and at about an inch beyond the distal end of the clavicle, united with the larger 

 portion of the muscle, with which it was inserted » close to the anterior vertebral angle 



o He scapula. Some fibres pass over the supraspinal, and are attached by fascia to 

 the spine of the scapula." 



lhe subclavius was absent in a specimen of Myrmecophaga tamandua (non-claviculate) 



1 Op. *t. p. 422, , A 



vol , p J • Tst n *1H 8e ° ^ Turner59 Pa * cr " 0n the ^^ Sternalis," *>«". of Anat. and Phys. 



'• i- P- ->". 1st senes. Cambridge 1867. 



: %",■ .",, A ;:r y ° f ^ Cre * d A ^«'" r™. Zool. B* June 1866, p. 308. 



arose 



