101 



490. Seven of the dorsal vertebrae. 



The spinous process of the first dorsal vertebra rises to twice the 

 height of the preceding spine of the seventh cervical, and preserves an 

 equal antero-posterior diameter from its base to its summit, which is 

 thick and slightly bent backwards : four or five succeeding dorsal ver- 

 tebra? give evidence of having been surmounted by spines of equal 

 height and strength. 



The fragments of the dorsal vertebrse and ribs of the Scelidotherium 

 closely conform, excepting in the greater relative height of the anterior 

 dorsal spines, with the Megatherioid type. 



491. The three lumbar vertebra?, which are not anchylosed to each other, or 



to the sacrum, as in the Mylodon robustus. 



492. The sacrum. This complete bone manifests in its great expansion poste- 



riorly, where it joins the ischium, in the capacious medullary cavity and 

 wide nervous foramina, a like conformity with the Megatherium which 

 is presented by the pelvis of the Mylodon, and a corresponding harmony 

 with the disproportionate bulk of the hind-legs. 



493. Portions of several of the vertebral ribs. 



494. The right scapula. 



495. The humeral half of the left scapula. 



The scapula of the Scelidothere in its double spine, in the osseous 

 arch formed by the confluence of the acromion with the coracoid process, 

 and in the substitution of a distinct foramen for the suprascapular notch, 

 agrees with that of the Megatherium : but the span of the acromial arch 

 is relatively wider, and the surface for the articulation of the clavicle is 

 better marked. The limits of the acromial and coronoid portions of the 

 arch are still definable in the present skeleton, indicating, with the unan- 

 chylosed condition of most of the epiphyses, the nonage of the individual. 



496. The proximal portion of the left humerus cemented to the foregoing 



scapula by the calcareous matrix. 



