280 ME. A. J. C. MOLYNETJX ON THE [May 1903, 



character together. There are minor faults in the coal-seams, but 

 in those observed the downthrow is only a few inches. 



The regional alteration extends for some distance on either side 

 of these lines of breccia, and the indurated rocks, resisting erosion 

 better than the unaltered loose-grained sandstones, consequently 

 form the core of the ridges, hills, and mountains of this part of the 

 country. 



IV. The Fossil Remains. 



In investigating these stratified areas, the importance of fossil 

 remains in determining their position in the geological record has 

 been continually borne in mind ; but, while constant search was 

 made, it was long before specimens could be found. The splitting- 

 up of rocks was seldom successful, and eventually it was found best 

 to examine the weathered surfaces of blocks in the open. 



The mounds of travertine occurring as superficial deposits from 

 thermal springs enclose recent land and freshwater shells, such as 

 Pupa, Planorbis, and Limncea, and are associated with silicified 

 trees. 



The red strata of the Forest Sandstones and Escarpment-Grits 

 have so far yielded no fossils, for their loose texture is not favour- 

 able to the preservation of organic remains, and there are few expo- 

 sures of finer and more compact sediments to search. 



The Upper Matobola Beds yield bivalve shells of unioniform 

 appearance, in an impure limestoue near Gunyanka's Kraal. On the 

 top of a slight rise, 3 miles south-east of Nkoka's Kraal, a ferru- 

 ginous shale contains similar but smaller specimens. In weathered 

 slabs near Gunyanka's, and embedded with these shells, numerous 

 pieces of bone are found, but in only two cases is there any definite 

 shape — one resembling a small shoulder-blade, 3 inches long, and 

 the other a phalangeal bone 4 inches in length. 



The buff and greenish clays of these beds contain calcareous 

 concretions, which, on decay of the softer portions, lie like shingle 

 on the surface of the plains. These are frequently septarian, but 

 the nucleus, when it can be separated out, never shows any definite 

 organic form. A pale-grey clay, lying near the base of these beds, 

 yields broken frustules of diatoms. 



The finer ferruginous portions of the Busse Series — which inter- 

 venes between the two groups of coal-bearing strata, or Matobola 

 Beds — contain impressions of SigillaHasjaA. Calamiles, and numerous 

 detached scales and imperfect bones of fishes. These fossils may 

 be found both east and west of Nkoka's Kraal, on weathered blocks, 

 and chipping open these rocks seldom results in larger or better- 

 preserved specimens being secured. The large slab exhibited at the 

 reading of this paper was found at the foot of the left bank of the 

 Busse River, 4 miles west of Nkoka's Kraal, where a capping of fine 

 ferruginous sandstone is seen to overlie dark shales. On other 

 blocks were many more fish-scales, but nothing so clear as the tail 

 and bones of the ganoid fishes contained in this slab. 



