Mr. Bain on Fossil Remains in South Africa. 57 



eastward ; and of this country the portion within view from the summit of the 

 Winterberg presents a correct epitome. 



The northern side of the Winterberg is without a vestige of wood, and is less steep 

 than the southern. The Tarka river rises on the descent to the north-west, and 

 after flowing in that direction about thirty miles, and then nearly the same distance 

 to the south-west, (in which course it passes through the extensive level plains, 

 named, after the river, the Tarka plains,) it falls into the Great Fish river. These 

 plains are bounded by a number of fantastically-shaped mountains, among which 

 are the TweeTafel Bergen, twenty miles north-north-west of the Winterberg peak. 

 In descending towards the military station, called Tarka Post, the peculiar forms of 

 the detached hills, with their basaltic cappings, begin to attract attention. I append 

 an outline sketch of this singular district, representing these cappings formed of 

 huge columns from 50 to 200 feet in height, resting on horizontal strata, and the 



basaltic dikes which traverse the strata. If we suppose the whole of these tabular 

 summits to have been once continuous, denudation, in order to reduce them to their 

 present disconnected state, must evidently have operated on a very gigantic scale. 



In the Tarka mountains, which may be regarded as a prolongation of the Win- 

 terberg range, a calcareous pisolite is found, unfit for lime-burning, owing to the 

 quantity it contains of alumina and oxide of iron. 



On the northern side of this range, at Tarka, I found remains of Bidentals ; and 

 I made the same discovery in the Graaff Reinet division, nearly 100 miles to the 

 west of Tarka. Moreover I have little doubt, from the recollection I have of some 

 osseous remains which were found some years ago in the district of Beaufort, about 

 100 miles further westward, that these also belonged to the same group of reptiles. 



What may be the geological position of the formation containing these reptilian 

 remains is a point not easily determined, in consequence of the difference there is, in 

 composition and external appearance, between the strata of South Africa and the 

 known and described strata of other countries. The difficulty is the greater, from the 

 extremelyrare occurrence of fossil shells ; for throughout the whole of the exten- 

 sive area in which reptilian remains occur, not a single shell has been discovered, 

 so far as my own researches have gone ; and except the instance of Mankazan, I 

 know only of one other in which such a discovery has been made. I here refer to 

 an Ammonite, which a friend of mine, dwelling at Cradock, found in situ, at the 

 summit of the Spitzkop, or Compass Berg, 7000 feet high, and the loftiest moun- 

 tain in South Africa; it lies 100 miles west-north-west of the Winterberg peak. 



