Tertiary Formatiom. 61 



pace of a large cuirassed quadruped, whose relations with the 

 skeleton to which it belongs have recently given rise to dis- 

 cussions among zoologists. Since 1770, the Pampas have be- 

 come celebrated by the discovery of the famous skeleton of 

 the Megatherium found at Lujan, which was sent to the King 

 of Spain by the Viceroy of Buenos- Ayres, and was described 

 by Cuvier and M. Garrega. In 1827, M. d'Orbigny collected 

 the fossil bones of several species in the Pampas, at San- 

 Nicolas to the north of Buenos- Ayres, on the Parana and 

 near Bajada, in the province of Entre-Rios. Some years af- 

 terwards, Mr Darwin discovered in the Pampas a great number 

 of remains of mammifera, which Mr Owen has described with 

 the greatest care in the '* Zoology of the Voyage of the Beagle."" 

 Since that time, MM. Tadeo Vilardebo, Bernardo Berro, and 

 Arsene Isabele, found, in 1838, on the banks of the Podemal, 

 one of the tributaries of the Rio Santa- Lucia, in the Banda 

 Orientale (Republic of Uraguay), the skeleton of an enormous 

 animal, still provided with its carapace, and to which they 

 have given the name of Dasypus giganteus. Lastly, in 1841, M. 

 Pedro de Angelis discovered in the Pampean bed, at a distance 

 of about seventeen miles north of Buenos- Ayres, the skeleton of 

 the Mylodon robustus, which is now deposited in the Museum 

 of the Royal College of Surgeons in London, and which Mr 

 Owen has described in a special work, that has excited, in 

 the highest degree, the attention both of zoologists and of 

 geologists.* There was also found at the same locality an 

 osseous carapace analogous to that of the armadillos, but of 

 gigantic dimensions. 



If we follow the Pampean deposit beyond the Pampas, we 

 find that the valley of Torija, situated in the south of the re- 

 public of Bolivia, in the last eastern lateral chains of the east- 

 ern Cordillera, has for a long time been quoted as a locality 

 of fossil bones. This valley forms a small basin furrowed in 

 the east by a water-course, and it is on the banks of the latter 

 that an immense number of bones occur in a gravelly loam, 

 in which the animals seem to be nearly entire. M. d'Orbigny 

 has ascertained the occurrence in this deposit of the Mastodon 

 Andiu7n of Cuvier, and he thinks that he can refer to the same 



* Owen's Description of the Skeleton of the Mylodon robuatiu, 1842. 



