Bibliographical Notices. 315 



o*f their habits and ranges." And it is at the same time modestly 

 added, "As I do not possess the knowledge requisite for such an un- 

 dertaking, several gentlemen have most kindly undertaken different 

 portions of the work." To Mr. Owen has been deputed the descrip- 

 tion of the fossil mammalia; to Mr. Waterhouse those of the recent 

 mammalia ; to Mr. Gould the birds ; Mr. Bell the reptiles ; and the 

 fishes to the Rev. L. Jenyns. The first part, as our title indicates, 

 is devoted to the fossil mammalia, described by Mr. Owen, to which 

 work and the admirable illustrations the Wollaston Medal was 

 awarded in February last by the Geological Society. This is pre- 

 faced by a Geological introduction by Mr. Darwin, detailing the lo- 

 calities where the remains afterwards noticed were discovered. 



All the remains were found between latitudes 31° and 50° on the 

 eastern side of South America ; in the provinces bordering the Plata; 

 Bahia Blanca, situated near the confines of Northern Patagonia, and 

 Southern Patagonia. . The principal deposit is contained in the al- 

 most boundless estuary of the Plata, forming a flat or pampa of red- 

 dish argillaceous earth, varying little in elevation and stretching over 

 a surface of some hundred miles in extent, where the traveller may 

 wander " without meeting a single pebble or discovering any change 

 in the nature of the soil." This is intersected by streams, which lay 

 open the immense deposits of animal remains which are there buried, 

 and exhibit to the traveller those wonderful relics which are com- 

 menced to be described in the work before us. Mr. Owen, consi- 

 dering the information communicated by Mr. Darwin, is of opinion 

 that this deposit cannot be of very ancient date, and the facts he 

 states seem to bear him out. The change of level which has taken 

 place is by no means considerable, and the numerous accompanying 

 remains of shells belong mostly to recent species, and to many which 

 are at this moment existing in the vicinity. He concludes that a 

 great bay formerly occupied what are now called the Pampas, and 

 the lower parts of Banda Oriental, and that into this the rivers which 

 are now united in the one great stream of the Plata must formerly 

 have carried down the carcases of the animals inhabiting the sur- 

 rounding country, and "where the skeletons would thus be en- 

 tombed in the estuary of mud which was then tranquilly accumula- 

 ting." The second district where quadrupeds were found is in 

 Bahia Blanca, about 250 miles south of the Plata ; it is a large bay 

 nearly surrounded by very low land, on which successive lines of 

 sand dunes mark in many parts the retreat of the waters ; and it is 

 supposed, from the bones being found imbedded in their proper rela- 

 tive positions, that the carcases of the animals when they perished 



