334 PALEONTOLOGY. 



in a hard, horny, or osseous crust, composed of innumerable 

 pieces, inlaid like mosaic, which covers the head, body, and 

 tail. This forms a shield which protects the front of the 

 body, and an extensive cuirass for the shoulders,' and the 

 croup. A series of intermediate transverse inoveable bands 

 permit the animal to roll itself into a ball like a hedgehog. 

 The tail is often encircled with rings of this substance, and 

 there are numerous plates on the legs. 



Amongst the most extraordinary of the extinct genera ot 

 this family, is the Glyptodon, or gigantic armadillo, which in 

 the structure of the skull, and form of the ascending branch 

 of the zygomatic arch, resembles the Dasypus, and connects 

 that genus with the Megatherium. The molars f _f approach 

 those of the armadillos in structure; their external surface is 

 grooved with two deep furrows, which divide the surface 

 of the tooth into three lobes hence the name. The hind 

 feet have a remarkable form ; the metatarsal bones are large 

 and massive ; the nail phalanges are short and depressed. 

 The Glyptodon was protected by a solid coat of mail, com- 

 posed of innumerable plates united by serrated sutures. 

 Internally these plates appear hexagonal, but externally they 

 form a mosaic of rosette-like figures. Its gigantic remains 

 were found in the sub-apennine stage of the Pampas of 

 Buenos Ayres ; they now enrich the museum of the College 

 of Surgeons, London. Fragments of the bony cuirass of 

 Glyptodon were supposed, before the discovery of this splen- 

 did specimen, to belong to the Megatherium* 



Chlamydotherium, Hoplophorus, Pachytherium, Euryodon, 

 Jtenurus, are fossil genera which have been found by Lund 

 in the ossiferous caverns of Brazil. Gigantic fossil species 

 of the existing genus Dasypus, have been found in the sub- 

 apennine stage of Prance, and in the caverns of North and 

 South America. Dasypus and Macrotherium are the only 

 edentate mammals found fossil in Europe. 



Third Family. The MEQATHEEID^ is composed of gi- 

 gantic slow-moving extinct genera, of which the Megatherium 

 is typical. The skeleton (see fig. 182) was fouud on the 

 banks of the Luxan, about three leagues from Buenos Ayres. 

 Similar remains have been found at Lima, and likewise at 



* Buckland's Bridgewater Treatise, p. 160. 



