GEOLOGY. 



45 



the entire skeleton of the great extinct " Ground- Sloth " {Mega- 

 therium Americanum), the separate original bones of the skeleton, and 

 the skull, occupying Wall-case No. .12, and Table-case No. 14. 



This colossal animal measures 18 feet in length, its bones being 

 more massive than those of the elephant. The thigh-bane is nearly 



D B 



Fig. 13.— Extinct Gigantic Armadillo (Glyptodon clavipes) from South America. 

 a, View of entire animal, b, Front end of carapace, c, Back view of same, d and e, 

 Upper and under side of skull, f, Section of tail showing caudal vertebras inside the 

 bony sheath. 



thrice the thickness of the same bone in the largest of existing 

 elephants, the circumference being equal to the entire length. The 

 strength of the Megatherium is indicated by the form of the bones, 

 with their surfaces, ridges and crests everywhere roughened for the 



Iig. 14.— Lower Jaw of Megatheriu Americanum, showing the chisel-shaped Molar Teeth. 



attachment of powerful muscles and tendons. The bony framework 

 of the fore-part of the body is comparatively slender, but the hinder 

 quarters display in every part enormous strength and weight com- 

 bined, indicating that the animal habitually rested on its haunches 



