THE WADSWORTH GALLERY. 23 



— referable to the Pleistocene period, because most of its shells are still 

 living in the ocean — that the Megatherium was entombed. Its bones are 

 almost exclusively found in the cliffs and steep banks of rivers ; thus far, 

 the Rivers Salado and Luxan. The race was not exterminated by some 

 great cataclysm ; for the small bones, like the kneecap, of a coteniporary 

 mammal were discovered by Darwin in the same deposit, all lying in their 

 proper relative position. Like the Aborigines of our own continent, like the 

 Dodo of Mauritius, the Edentate giants perished one after another, in the 

 lapse of infinite ages, by those changes of circumstances in the organic and 

 inorganic uorld which are always in progress. 



The Megatherium was buried in a hecatomb of extinct monsters. By its 

 side we find the bones of the kindred Mylodon, Megalonj^x and Scelidothe- 

 rium, all of them Sloths ; the Grlyptodon and Schistopleurum, the Toxodon 

 and Mastodon, the Machairodus and Macrauchenia. The Megatherium and 

 its associates have been discovered in the Pleistocene deposits of the United 

 States ; but South- America was then, as it is now, the metropolis of the 

 Edentates. 



The great skeleton is surrounded by a beautiful iron railing, the columns 

 of which support bronze figures of ten representative forms from the natural 

 order (Edentata) to which the fossil belongs. They are the Mylodon {M. 

 robz/^tus), Megalon jK [M. jeffersojii), G\j\)todon {G. davicaudat us), Sloth 

 {Bradypus didactylus), Great Anteater [Myrmecophaga juhata), Little Ant- 

 eater (Af. didactyla), Armadillo {Dasypus peha), Aard Yark [Orycteropus 

 capensis), Pichiciego {Clamyphorus truiicatus), and Longtailed Manis {M. 

 longicaudatus). The animals of this series, by their similarity in certain 

 parts, illustrate well the law of adherence to type or pattern, which Nature 

 followed in their construction ; while their differences illustrate the other 

 great law by which organic structures are specially adapted to special modes 

 of life. 



Scliistopleuriiiii fypiiSo 



In front of the Megatherium, and hardly less imposing, is the groat fossil 

 Armadillo from the same Panipean deposit, the iSchistopleuruni typus.^ The 

 original was found near Montevideo in 1S46, on the borders of the River 

 Luxan, by Dr. F. X. Numez ; and presented, by order of the Dictator 

 Rosas, to Vice-Admiral Dupotel, who gave it to the Museum of Dijon, 

 his native city. M. Nodot, Curator of the Museum, describes it in the 

 Memoirs of the Academy of Dijon in 1856. Like the Megatherium, it be- 

 longed to an age when nearly all families of mammals were represented by 

 larger forms than at the present day. 



The body is covered by a ponderous coat of mail ( the original weighs 

 about 4030 lbs.) formed by polygonal plates,* none of which are disposed in 

 bands as in the living Armadillo, but which were all firmly articulated to 

 each other : the animal, therefore, could not contract or bend its body into 

 a ball as does its modern puny representative. This specimen received its 

 generic title because it seemed to show the beginning of such a division : 

 the carapace is much warped, and, in several places, indented, probably 

 during the life of the animal. It measures six feet eight inches in length and 

 nine feet two inches across, following the curve, at the middle of the back. 

 The skull was likewise defended by a tessellated bony casque, and is also 

 remarkable for the long backward-curved apophysis descending from the 

 zygoma as in the Megatheroids.t The animal possessed a clavicle, yet seized 



* In the Soliistopleurum, these plates or ossicles are mostly hexagonal; in the 

 Glyi)ii»(lan. p;;ntagonal 



t The skull is wantiug ia this cast, but will soou bo added. 



