OSSEOUS SYSTEM OF MAMMALIA. 85 



double spinous ridge, indicating great muscular development ; the strong 

 clavicle, 6 ; the short, thick humerus, c, with its rugged tuberosities ; the 

 stout fore-arm, d ; the hook-like olecranon, e, of the ulna ; the firmly 

 knit union of the bones of the carpus (differing in number, in different spe- 

 cies), with those of the fore-arm, and with each other ; the strength of 

 the well-armed fingers ; and the compact and solid structure of the whole 

 hand, indicate the purpose for which it is especially designed. Nor is this 



Skeleton of the Chlamyphorus. 



indication less evident in the Chlamyphorus (fig. 87) ; an animal which, 

 while it approaches, in some points of its structure, to the Mole, displays 

 a still more decided affinity to the Armadillo. The scapula, a, is here, 

 also, spacious, with a double spinous projection ; the clavicles, b, distinct, 

 and largely developed ; the bones of the arm prodigiously thick and 

 irregular ; the hands stout and short ; and the fingers enveloped in large 

 spatulate nails. It is somewhat remarkable that, though the clavicle is 

 so perfect in the Armadillo, and in most of the Edentata, as the Sloth, Ant- 

 eaters, &c., it is not found in the Great Ant-eater (Myrmecophaga 

 jubata), nor in the Pangolins (Manis) ; though the hands of these animals, 

 armed with claws of immense size, are expressly adapted for digging. 

 In the Ornithorhynchus and the Echidna, the bones of the arm and 

 shoulder are very remarkable ; an approximation, in the structure of the 

 latter, to that of birds, and, still more, that of 

 Lizards, being very apparent. The scapula, 

 in the annexed representation of the chest and 

 shoulder of the Echidna (fig. 88), is large and 

 strong, its shape somewhat resembling that 

 of a Turkish cimeter, being indented with a 

 semilunar hollow on its posterior margin : it 

 is concave on its external surface, so that 

 it does not adapt itself to the arch of the 

 ribs. The sternum consists of four portions, 

 chest of the Echidna. exclusive of a bone conjoined to its anterior 



extremity, termed, by Cuvier, the Y-shaped bone, a, a, from its resem- 



