viit PANOCHTHUS AND GLYPTODON 185 



some Armadillos, the cervical vertebrae are at least partly fused. 

 The atlas is free, but the rest, or at any rate five of them, are 

 united. The last cervical is sometimes fused with the succeeding 

 dorsals ; the latter are twelve in number, and are fused together 



' ' O 



so far as concerns their centra and neural processes. The 

 succeeding region of the vertebral column includes seven to nine 

 lumbars, which are fused with the eight sacrals ; in this region the 

 neural processes are high, and there is thus produced a strong and 

 lofty ridge along the back, which forms a powerful support for 

 the carapace. The fore-limbs are shorter than the hind-limbs, 

 which latter are attached to an unusally massive pelvis. The 

 claws of the limbs are blunt and almost hoof-like. 



The heavy carapace consists of sculptured, five or six-sided 

 plates, which have no particular arrangement in the middle, but 

 towards the margins show indications of an arrangement in trans- 

 verse rows. The moderately long tail is also encircled by bony 

 skin-plates which are thorny above, or at least provided each with 

 a blunt upstanding process. It appears that outside this bony 

 system of scutes were horny epidermic scales, corresponding 

 exactly with the tesserae which they cover. There are apparently 

 a good many species of Glyptodon. 



In the allied genus Panochthus the tail is rather longer, and 

 the bony rings which surround it, instead of being all movable 

 as in Glyptodon, are at first so, but later, i.e. towards the end of 

 the tail, become welded into a single and massive piece. Both 

 feet are here four-toed, while in Glyptodon the hind-feet are five- 

 toed and the fore-feet four-toed. 



Daedicurus shows a further specialisation, in that the feet have 

 three and four digits respectively. The orbit too shows a 

 specialisation in being separated from the temporal fossa. The 

 descending process of the zygomatic arch is not so extraordinarily 

 exaggerated as it is in Glyptodon. It has the same terminal 

 tube of osseous scutes upon the tail. This creature seems to have 

 reached a length of about twelve feet. 



Propalaeokoplophorus is, unlike the great Armadillos that we 

 have hitherto dealt with, a small animal, not exceeding 2 feet 

 or so in length of carapace. A small alveolus on each side of the 

 premaxillae seems to suggest the former presence of an incisor 

 tooth ; and it seems that the animal possesses both true molars 

 and premolars; for the first four of the eight teeth are much 



