Fauna and Stratigraphy of the Stormberg Series. 449 



stone with the massive white Jurassic sandstone from the Grand 

 Canon region of Arizona. 



Under the microscope the rock is very uniform in texture, chielly 

 made up of grains of clear quartz only slightly rounded. Angular 

 fragments of orthoclase and rnicrocline occur, as well as plagioclase, 

 small grains of zircon, epidote, and sometimes tourmaline. 



At Siberia, in Wodehouse, a shale-band near the base of the 

 formation has yielded a fragmentary fish, many specimens of Lepidurxx. 

 numerous Cyzicus and Ostracods, and several forms of insect. In 

 other places silicified wood is not uncommon. 



Structurally, the sandstone is seen to be eroded and faulted before 

 the main outpourings of the lava. 



At Lady Grey, Aliwal North Division, where the Cave Sandstone 

 is very well seen, the lower bed of sandstone is approximately 80 feet 

 thick and is underlain by a few feet of soft reddish sandy shales. 

 This bed is without sign of bedding planes, but exhibits well-marked 

 vertical jointing. Above it is 400 ft. of sandstone clearly exhibiting 

 a rude stratification in its upper portion and noticeable false-bedding 

 at more than one horizon. 



Orange Free State. Along the western border of the Drakensbrig 

 mass the Cave Sandstone constantly appears above the Red Beds. 

 On Thaba'Nchu mountain it varies in thickness from 150 feet to 

 !250 feet. Its thickness at Harrismith is 250 feet, where it is overlain 

 by columnar dolerite, and at Verkijkersberg 500 feet. Its features 

 are constant, a creamy or white massive sandstone forming the main 

 body of the rock. At Fouriesburg the base of the formation is red 

 and purple passing into white, so that it is impossible to draw a 

 lithological distinction between the Cave Sandstone and the top of 

 the Red Beds. From this level have come the types of Gryponyx 

 africanus and Massospondylus harriesi as well as other lightly-built 

 forms. A shale-band in the Cave Sandstone of Harrismith yielded 

 Cyzicus draper i in various stages of growth. 



Transkei. At the extreme North-east of the district the formation 

 has a thickness of 800 feet; but a few miles away it thins to 50 feet. 

 There is here an interruption of deposition caused by volcanic out- 

 bursts. At Tent Kop the Cave Sandstone is altogether absent, the 

 lavas resting directly upon the Red Beds. These ashes dip beneath 

 the Cave Sandstone of the neighbouring areas. 



Lithologically the Cave Sandstone is uniform throughout the area - 

 white to cream in colour, sometimes deep pink or red towards the 



