ORDER EDENTATA. 



1293 



genera and species ; but they may be either plain or tuberculated. 

 There is usually a ventral buckler (never found in the Armadillos), 



Fig. 1162. — Glyptodon clavipcs] Pleistocene, South America. Reduced greatly. The tail is 

 incorrectly restored, and it is probable that the figured portion belongs to Hoplophorus. 



and 



the tail 



8 



enclosed in a complete bony sheath. The 



Fig. 1163. — Grinding surface of two teeth of 

 Glyptodon rcticulatus ; from the Pleistocene of 

 South America. 



teeth are - in number, and have two deep grooves on either side 

 8 



dividing them into three nearly 



distinct lobes (fig. 11 63); the 



generic name being derived from 

 this grooving or fluting. The 

 facial part of the cranium is char- 

 acterised by its extreme shortness 

 (fig. 1 163^); and there is a 

 long descending maxillary pro- 

 cess in the zygomatic arch. Nearly the whole of the vertebral 

 column is anchylosed into a long tube, but there is a complex 

 joint at the base of the neck. This 

 family is mainly characteristic of 

 South America ; but species of 

 Glyptodon ranged as far as Mexico 

 and Texas into North America. 

 Great confusion has arisen in re- 

 spect to the classification of the 

 Glyptodonts, owing to the diffi- 

 culty of referring isolated caudal 

 sheaths to their proper carapaces. 

 The forms with a solid carapace 

 may, however, be arranged as fol- 

 lows. In Hoplophorus the scutes 

 of the carapace are sculptured, and 

 often comparatively thin, the peripheral series being flat ; while the 

 caudal sheath has several movable rings, and terminates in a long 



Fig. 116202s. — Left lateral view of the 

 skull of Glyptodon; from the Pleistocene 

 of South America. One-tenth natural 

 size. (After Burmeister). 



