286 Quadrupeds. 



larger frequently descend, and pass a considerable portion of their lives on the ground. 

 So, also, in the ant-bears, the smallest species of all lives entirely in trees ; those ol 

 middle size feed principally on the ground, but also ascend trees ; while the very lar. 

 gest have the ground assigned them for their perpetual abode. It therefore very 

 sonably excites our astonishment, to find that in a former period of creation, such enor 

 mous monsters should have had trees allotted them for their habitat." — Id. 1. c. p. 210 



But it is time that we turn to Professor Owen's dissertation, which 

 is certainly the most complete analysis of a fossil skeleton that it has 

 ever been our good fortune to peruse. First, we have the history of 

 the fossil. 



" The skeleton which is the subject of the present memoir, was discovered in th( 

 year 1841 by M. Pedro de Angelis, seven leagues north of the city of Buenos Ayr 

 in the fluviatile deposits constituting the extensive plain intersected by the great Ri< 

 Plata and its tributaries, and which has been raised during a recent geological epocl 

 above the level of the sea. 



" In this formation, and most probably anterior to its elevation, the animal mus 

 have been buried entire ; and, if the present heat of the climate prevailed, soon aftei 

 its death : for the parts of the skeleton were found little disturbed, and the very ie\ 

 bones that are wanting are such as would be likely to escape the search of the mos 

 diligent collector. 



" About the same time, and near the same place, a tesselated osseous carapace of 

 some large quadruped, like an armadillo, was exhumed ; and information of this dis- 

 covery having been communicated to the Royal College of Surgeons by Sir Woodbine 

 Parish, late H.M. Charge d'Affaires at Buenos Ayres, both this carapace and the above 

 mentioned skeleton were purchased by the College. They arrived in November 1841, 

 in many pieces, fragile from the loss of the animal matter ; but after having been re- 

 stored in some measure to their original tenacity, the parts of the carapace were re- 

 united, the skeleton was articulated, and both are now placed in the Museum." — Prof. 

 Owens Memoir, p. 3. 



We have next the history of similar remains as far as hitherto re- 

 corded, together with a sketch of the views of the respective authors, 

 in the course of which the conclusions of Dr. Lund are given, but 

 pronounced to be somewhat startling. Then we are presented with 

 a concise description of the skeleton, in the following words. 



*' The singularly massive proportions of the skeleton of the Mylodon robiistus ar- 

 rest the attention of every observer, and are not less calculated to excite the surprise of 

 the professed comparative anatomist. 



" A trunk, shorter than that of the Hippopotamus, is terminated behind by a pel- 

 vis, equalling in breadth and exceeding in depth that of the Elephant. This capacious 

 bony basin rests on two massive but short hind extremities, terminated by feet as long 

 as the femora, set at right angles to the leg, as in the plantigrade animals, but with 

 the sole slightly turned inwards. 



" A tail equalling the hind limbs in length, and proportionally as thick and strong, 

 assists in supporting, rather than depends from, the broad sacral termination of the 

 pelvis. 



