EDENTATA. 305 



while the first molar is large, pointed, and separated from 

 those behind it by a Avide gap. The fore-limbs are shorter 

 than the hind-limbs, and the calcaneum is excessively long. 

 In the Pliocene or Post-Pliocene deposits of Cuba occur the 

 remains of the genera Megcdocnus and MyomorijJius, which 

 are nearly allied to Mcgalonyx. 



The great Ground -sloths, of which the principal types 

 have now been briefly glanced at, not only have no repre- 

 sentatives at the present day, but do not even appear, so 

 far as certainly known, to have survived into the earlier por- 

 tion of the Eecent period, their last recorded occurrence 

 being in the bone-caves of Brazil. On the other hand, it 

 is in the deposits of these caves that we first meet with 

 remains of the existing Sloths (Bradypodidce), which make 

 their appearance here under various extinct types, such as 

 Cmlodon and Ockothermm. 



The living families of the Dasypodidm and Myrmeco- 

 pliagidce, both characteristic of South America, were repre- 

 sented, similarly, by numerous interesting types which flour- 

 ished in the same geographical area during late Pliocene and 

 Post-Pliocene times. Most of these types, though clearly 

 representative of those now existent, differed from the latter 

 in points of generic importance, while many were of com- 

 paratively gigantic dimensions. Thus, side by side with the 

 huge Megatheroids which took the place of the existing 

 herbivorous Sloths, we find the colossal Glyptodons, repre- 

 senting the little banded and cuirassed Armadillos {Dasy- 

 podidce) of the South America of to-day, and, like these, 

 adapted for a carnivorous diet. Taking Ghjptodon itself 

 (fig. 613) as the type of this singular group of extinct 

 Armadillos, we are presented with a large Edentate, the 

 upper surface of which was protected by an armour formed 

 of dermal ossifications or scutes. The head is covered with 

 a helmet of bony plates, and the tail was enclosed in a com- 

 plete cylindrical casing similarly composed. The trunk- 

 armour is formed of nearly hexagonal bony scutes, forming 

 a massive dome, for the support of which the skeleton is 

 specially modified. Thus tlie last cervical and first two 

 dorsal vertebrae are anchylosed to form a single bone 



VOL. II. U 



