1833. | BAHIA BLANCA. 8] 
CHAPTER V. 
Bahia Blanca—Geology—Numerous gigantic extinct Quadrupeds—Recent 
Extinction—Longevity of Species—Large Animals do not require a luxu- 
riant vegetation—Southern Africa—Siberian Fossils—Two Species of 
Ostrich—Habits of Oven-bird—Armadilloes—Venomous Snake, Toad, 
Lizard—Hybernation of Animals—Habits of Sea-Pen—Indians Wars and 
Massacres—Arrow-head, antiquarian Relic, 
BAHIA BLANCA. 
Tue Beagle arrived here on the 24th of August, and a week after- 
wards sailed for the Plata. With Captain Fitz Roy’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 
en a previous occasion, when the Beagle was employed in sur- 
veying 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 eleva- 
tion we have evidence in upraised beds of recent shells, and in 
rounded pebbles of pumice scattered over the country. At 
Punta Alta we have a section of one of these later-formed little 
plains, which is highly interesting from the number and extra- 
ordinary character of the remains of gigantic land-animals em- 
bedded in it. These have been fully described by Professor 
Owen, in the Zoology of the voyage of the Beagle, and are depo- 
sited 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 Megathe- 
rium, the huge dimensions of which are expressed by its name. 
Secondly, the Megalonyx, a great allied animal. Thirdly, the 
Scelidotherium, also an allied animal, of which I obtained a 
