76 BAHIA BLAXCA. [ciiAp. v.. 



CHAPTER V. 



Bahia Blanca Geology Numerous gigantic extinct Quadrupeds Recent 

 Extinction Longevity of Species Large Animals do not require a 

 luxuriant vegetation Southern Africa Siberian Fossils Two Species 

 of Ostrich Habits of Oven-bird Armadilloos Venomous Snake, 

 Toad, Lizard Hybernatiou of Animals Habits of Sea-PenIndian 

 Wars and Massacres Arrow-head, antiquarian Relic. 



BAHIA BLANCA. 



THE Beagle arrived here on the 2ith of August, and a week after- 

 wards sailed for the Plata. With Captain Fitz Boy's consent I 

 was left behind, to travel by land to Buenos Ayres. I will here 

 add some observations, which were made during this visit and on 

 a previous occasion, when the Beagle was employed in surveying 

 the harbour. 



The plain, at the distance of a few miles from the coast, belongs 

 to the great Pampean formation, which consists in part of a reddish 

 clay, and in part of a highly calcareous marly rock. Nearer the 

 coast there are some plains formed from the wreck of the upper 

 plain, and from mud, gravel, and sand thrown up by the sea during 

 the slow elevation of the land, of which elevation we have evidence 

 in upraised beds of recent shells, and in rounded pebbles of pumice 

 scattered over the country. AtPunta Alta we have a section of one 

 of these later-formed little plains, which is highly interesting from 

 the number and extraordinary character of the remains of gigantic 

 land-animals embedded in it. These have been fully described by 

 Professor Owen, in the Zoology of the voyage of the Beagle, and are 

 deposited in the College of Surgeons. I will here give only a brief 

 outline of their nature. 



First, parts of three heads and other bones of the Megatherium, 

 the huge dimensions of which are expressed by its name. Secondly, 

 the Megalonyx, a great allied animal. Thirdly, the Scelidotherium, 



