116 



fied to form the base of a column destined to support an enormous 

 superincumbent weight, such as must have resulted from the thick ossi- 

 fied integument of this bulky loricate quadruped ; whilst in regard to 

 the Megatherium one would infer that the bulky body had not been 

 covered by an expanded bony coat of mail, from the very circumstance 

 that the toes were developed to sustain and wield long and compressed 

 claws, such as form the compensating weapons of defence of the hair-clad 

 Sloths and Anteaters. The ungual phalanges of the mailed Armadillos, 

 in their shorter, broader, and flatter form, make a much nearer approach 

 to those of the Glyptodon. But when the bones of the hinder extre- 

 mity above described are arranged in their natural relative positions, they 

 present to our observation the framework of a foot of such a construction 

 and form as is without a parallel in the animal kingdom : the nearest ap- 

 proach to its broad, thick, short and massive proportions is made by the 

 skeleton of the fossorial extremity of the Mole ; but it is the fore-foot 

 only of this animal that can be compared, in the compressed bulky figure 

 of the metacarpals and proximal and middle phalanges, with the singular 

 hinder extremity of the Glyptodon clavipes. The hind-foot of the Mole 

 resembles, in the lengthened metatarsal and phalangeal bones, that of the 

 existing Armadillos, and the generality of unguiculate quadrupeds. 



541. The almost entire carapace of the Glyptodon clavipes. 



It is composed of thick, pentagonal ossicles united together at their 

 margins by sutures : smooth on the inner surface where the sutures are 

 most conspicuous, rough and sculptured on the external surface according 

 to a definite pattern characteristic of the species, the whole forming a 

 symmetrical, oval, convex, bony case or shell which covered and defended 

 the upper and lateral parts of the entire trunk of the animal. 



The following are the dimensions of this carapace : — 



feet, inches. 

 Length, following the curve of the back 5 7 



Ditto in a straight line, or the chord of the arc 4 8 



Breadth, following the curve of the middle of the back .... 7 4 



Ditto in a straight line, or the chord of the arc 3 2\ 



Ditto of the anterior outlet or arched margin, at the base of the arch 1 5 



Ditto of the posterior outlet, at do 1 8 



