1833.] EXTINCT QUADRUPEDS. 77 



also an allied animal, of which I obtained a nearly perfect skeleton. 

 It must have been as large as a rhinoceros : in the structure of its 

 head it comes, according to Mr. Owen, nearest to the Cape Ant- 

 eater, but in some other respects it approaches to the armadilloes. 

 Fourthly, the Mylodon Darwinii, a closely related genus of little 

 inferior size. Fifthly, another gigantic edental quadruped. Sixthly, 

 a large animal, with an osseous coat in compartments, very like 

 that of an armadillo. Seventhly, an extinct kind of horse, to which 

 I shall have again to refer. Eighthly, a tooth of a Pachydermatous 

 animal, probably the same with the Macrauchenia, a huge beast 

 with a long neck like a camel, which I shall also refer to again. 

 Lastly, the Toxodou, perhaps one of the strangest animals ever 

 discovered : in size it equalled an elephant or megatherium, but 

 the structure of its teeth, as Mr. Owen states, proves indisputably 

 that it was intimately related to the Gnawers, the order which, at 

 the present day, includes most of the smallest quadrupeds : in 

 many details it is allied to the Pachydermata : judging from tho 

 position of its eyes, ears, and nostrils, it was probably aquatic, like 

 the Dugong and Manatee, to which it is also allied. How wonder- 

 fully are the different Orders, at the present time so well separated, 

 blended together in different points of the structure of the Toxodon ! 



The remains of these nine great quadrupeds, and many detached 

 bones, were found embedded on the beach, within the space of 

 about 200 yards square. It is a remarkable circumstance that 

 so many different species should be found together ; and it proves 

 how numerous in kind the ancient inhabitants of this country must 

 have been. At the distance of about thirty miles from Punta Alta, 

 in a cliff of red earth, I found several fragments of bones, some of 

 large size. Among them were the teeth of a gnawer, equalling in 

 size and closely resembling those of the Capybara, whose habits 

 have been described ; and therefore, probably, an aquatic animal. 

 There was also part of the head of a Ctenomys ; the species being 

 different from the Tucutuco, but with a close general resemblance. 

 The red earth, like that of the Pampas, in which these remains 

 were embedded, contains, according to Professor Ehrenberg, eight 

 fresh-water and one salt-water infusorial animalcule; therefore, 

 probably, it was an estuary deposit. 



The remains at Punta Alta were embedded in stratified gravel 

 and reddish mud, just such as the sea might now wash up on a 

 shallow bank. They were associated with twenty-three species of 



