VIII 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 
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-limhs, 
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. 
Propalaeohoplophorus is, unlike the great Armadillos that we 
have hithérto 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 
