DENUDATION OF WEALDEN. 645 



MIOCENE FAUNA OF THE SEWALIK HILLS, p. 182. 



The genus Dinotherium, so characteristic of the Falunian or Upper 

 Miocene period in Europe, occurs in India in strata of the same age. 

 But as yet it has only been found in Perim Island, in the Gulf of Cam- 

 bay, and not among the fossils of the Sewalik or Sub-Himalayan Hills, 

 as stated by mistake in the text (p. 182). Seven species of Sewalik 

 elephants have been alluded to, whereas the number is in fact only five, 

 three of which are referred by Dr. Falconer to the sub-genus Stegodon, 

 comprising forms intermediate between the Mastodon and Elephant. 

 The hippopotamus mentioned in the same page (182), belongs to the 

 sub-genus Hexaprotodon, a form now extinct. The Anoplotherium 

 posterogenium, supposed when first discovered to present a generic link 

 between the Sewalik fauna and that of the Eocene period, is now rec- 

 ognized as a species of Chalicotherium (Anisodon of Lartet), a genus of 

 pachyderms intermediate between the Rhinoceros and Anoplothere. The 

 same genus occurs in Miocene or Falunian strata at Sansan, in the 

 department of Gers, in the South of France. Among the Sub-Himalayan 

 fossils, a giraffe, camel, and large ostrich may be cited as proofs that 

 there were formerly extensive plains where now a steep chain of hills, 

 with deep ravines, runs for many hundred miles east and west. 



Fifteen species of freshwater shells of the genera Paludina, Melania, 

 Ampullaria, and Unio were obtained by Sir P. Cautley and Dr. Fal- 

 coner from the same strata, and, when shown by them in 1846 to the 

 late Prof. E. Forbes, were pronounced by him to be all extinct or un- 

 known species, with the exception of four, which are still inhabitants of 

 Indian rivers. Such a proportion of living to extinct species of Mol- 

 lusca agrees well with the usual character of an upper Miocene or 

 Falunian fauna, as observed in Touraine, or in the basin of Vienna and 

 elsewhere. 



DENUDATION OF THE WEALDEN. (Ch. XIX. pp. 271, 285.) 



Denudation of the Wealden — Discovery of the Lower Crag on the summit of 

 the North Downs between Folkestone and Dorking. 



The arguments adduced in the 19th chapter, pp. 271 — 285, to prove 

 that the denudation of the Wealden area took place at many successive 

 periods, and at dates widely remote from each other, some of them an- 

 tecedent to the deposition of the Lower Eocene strata of Great Britain, 

 and others so late as the Pliocene epoch, have lately received an unex- 

 pected confirmation, for Mr. Prestwich has announced to the Geological 

 Society of London (January 21st, 1857) the discovery of marine sands 



