54 Transactions of the South African Philosophical Society. 



square miles; in Basutoland (the whole of that country) 10,300 



square miles ; but their extent in the Orange Eiver Colony and over 



Natal can only be guessed at roughly. 



The Stormberg series is divided up as follows, in descending 



order : — 



4. Volcanic beds. 



3. Cave sandstone. 



2. Eed beds. 



1. Molteno beds. 

 The characters and extent of each of these divisions will have to 

 be briefly described, in order to ascertain the conditions under which 

 they were laid down. 



II. — The Sedimentary Eocks. 



The lowest of these, the Molteno beds, have been so named by 

 reason of their typical development around the town of Molteno, and 

 are of great importance economically, inasmuch as they contain the 

 only workable seams of coal known to occur in the Cape Colony. 



The Molteno beds consist of bands of sandstone (varying from 

 fine-grained greyish varieties to coarse gritty quartzose or felspathic 

 grits), and dark shales and mudstones usually weathering to pale 

 blue, yellow, or buff, with occasional seams of black carbonaceous 

 shale and coal. 



The remains of plants are abundant in the softer beds, and their 

 examination has led to the assigning of the Molteno beds to the 

 stage known in Europe as the Ehaetic. 



The formation crops out over the flattish ground at the foot of the 

 Drakensberg, and on the western border of Basutoland, but in the 

 Stormberg area the beds form fairly high ground, owing to their 

 general easterly dip. 



In the west the Molteno beds have a thickness of from 1,000 to 

 1,200 feet, but this increases in the Transkei, so that in Xalanga 

 and Elliot they are about 1,800 feet thick. 



How they vary in Maclear, and still further to the north-east, is 

 not yet known. 



In marked contrast to the Molteno beds comes the over- 

 lying division known as the Eed beds ; for in the latter the rocks 

 are usually highly-coloured. Beds of pale yellow and white sand- 

 stones are numerous; but the softer rocks are sandstones, shales, mud- 

 stones, and clays of red or purple colour, while green, bluish or yellow 

 tints are also common. The colouring is more intense in the upper 

 part of the Eed beds, especially where the rocks are freshly exposed. 

 Fossil remains are not very abundant ; vegetable life is represented 



