Fauna and Stratigraphy of the Stormberg Series. 481 



Wodehouse Division. Here is a 20 feet zone of finely-bedded blue 

 and green shale containing abundant fossils among which have been 

 recognised one imperfect lish, several examples of insects and nu- 

 merous examples of a small Ostracod, a Ci/zicits in various stages of 

 growth, and of an Aptis-\(ke Phyllopod, Lepidurus. The crustacean 

 part of this fauna is all of a semi-arid facies, capable of living in 

 damp or even dry mud for many months of the year even as they 

 or their near relations do in the Karroo to-day. Fish are also found 

 in what is supposed to be Cave Sandstone near Ficksburg, 0. F. S., 

 from which place slabs have been quarried with numerous specimens 

 of Semionotus capensis on each, the occurrence seeming to indicate, 

 from the fish point of view, a sudden catastrophic dessication of 

 their living quarters. 



Further, the Rev. S. S. Dornan has recorded that many fossil 

 fish occur in the Cave Sandstone at Masitisi, Basutoland, as well as 

 silicified trunks of trees. 



It is of interest here to consider a little more closely the physical 

 conditions of deposition, other than climate, of the Cave Sandstone 

 in the Cape-0. F. S. area. 



Although in places there is a gradual transition from the Red 

 Beds to the Cave Sandstone indicating absolute continuity of depo- 

 sition from one to the other especially in the North, in other places 

 there is undoubted unconformity so that, while in some parts of the 

 area deposition was going on, in other parts erosion was being 

 effected at a greater rate than deposition. 



As an extreme instance of this we may cite the fact that at 

 Glenelg in the Maclear District the Cave Sandstone rests directly on 

 pebbly grits of the Molteno Beds - - the Red Beds having entirely 

 disappeared. Here it does not seem certain whether the Red Beds 

 were eroded subsequent to the deposition of the main mass of the 

 formation and before the deposition of the Cave Sandstone, by means 

 of a strong scouring agency, or whether the absence of Red Beds is 

 to be explained by a continuous "contemporaneous erosion". 



"We have already referred to the unconformity which occurs in 

 the neighbourhood of the ancient volcano at Thule. At Tent Kop, 

 in the Maclear district, a bed of volcanic ash rests on the Red Beds 

 and underlies the Cave Sandstone; while other examples might be 

 cited showing that volcanic activity began, at any rate in the South, 

 before the deposition of the Cave Sandstone. 



At Tent Kop the sandstone overlying the Ash bed is full of small 

 angular inclusions of indurated sandstone and shale. 



That volcanic activity was rife during the formation of the Cave 



