137 



one of the perfections of form, adapting that animal to its subterra- 

 neous mode of life. In the Armadillo, however, the burrows serve 

 only as temporary retreats ; for it is endowed with powers of rapid 

 progression on the surface, and its organ of vision, though small, is 

 accordingly perfect. Thus the pelvis is destined to afford attach- 

 ment to numerous and powerful muscles, and the hind-legs are 

 evidently of considerable use in clearing out the burrow, as may 

 be inferred from the action of the Armadillo when he hides him- 

 self in the straw, which he throws behind him with great force : 

 whereas in the Mole, the whole power of digging is concentrated in 

 the anterior extremities, the peculiar mechanism of which is admi- 

 rably adapted to that act. 



" The caudal vertebrae, like the cervical, present in Dasypus a pe- 

 culiarity which is also found in the Cetacea, viz. that of having infe- 

 rior spines, or V-shaped bones. These are present beneath all but the 

 two last vertebrce j they are of a triangular form, but are articulated, 

 not by their bases, as in the Whale) but by their apices ; or rather the 

 part which corresponds to the apex is flattened, and produced into 

 two lateral processes. 



" With respect to the bones of the extremities, it may be remarked 

 that the scapula is very concave towards the ribs, more so than in the 

 nine-banded species ; and that besides the two spines, there is also a 

 third ridge near the superior costa. Below the articular surface on 

 the inferior costa there is also a little tubercle, which does not exist 

 in Das. Peba. The supra-spinal notch is large, and the acromion 

 long and narrow, but not anchylosed, as in the Sloth and Megathe- 

 rium, to the coracoid. The length of the scapula, from the base to 

 the articular surface, is 2 inches 1 line ; of the base, 2 inches j of the 

 acromion, 1 1 lines. The clavicles in Das. 6-cinctus are slightly 

 curved, and are shorter and stronger than in Das. Peba : their length 

 is 1 \ inch. There is thus a correspondence between the clavicle 

 and the rest of the anterior extremity, the claws being stronger, 

 and the whole of the bones shorter and thicker than in Das. Peba. 

 The humerus measures in length 2 inches 3-10ths : at the upper 

 extremity are two large tuberosities and a deep middle groove j 

 about the middle of the bone is a strong deltoid process : the bone 

 is considerably twisted, and the inner condyle perforated as in most 

 Edentata. The supinator ridge is strongly marked; the anconeal 

 fossa large and shallow. 



" The ulna measures in length 2 inches 3-1 Oths ; it is a very strong 

 bone, compressed, and arched backwards : the extremity of the ole- 

 cranon is bent backwards in the form of a hook : the lower extre- 

 mity has an equal share with the radius in the articulation with the 

 carpal bones. The radius is in length 1 inch 4 lines. The large pal- 

 mar sesamoid bone, formed at the expense of the tendons of the^exor 

 profundus digitorum y is shaped like the head of a spade, with the 

 concavity towards the carpus, and the sharp margin anterior : in length 

 and breadth it measures half an inch. It is articulated by a distinct 

 capsule and synovial membrane with the ossa pisiforme and cuneiforme 

 on one side, and to the navicularc on the other. The^exor profundus 



