160 WITTEBERG FOSSILS 



Little value can be set upon the determinations in the 

 above list, but it is of interest to note that all the genera 

 occur in the carboniferous rocks of Europe, and the 

 Cyclostigma is very like a fossil described by Feistmantel 

 from the Goonoo-Goonoo beds (Devonian or Carbonifer- 

 ous) of New South Wales. 



By far the most abundant fossil, if it be one, is 

 Spirophyton, but Prof. Seward, 1 who has examined some 

 of the specimens collected by the Cape Survey, is of 

 opinion that these markings are not of organic origin. 



Spirophyton is found as an impression extending 

 spirally through several inches of rock, with the curved 

 striations radiating from a central depression to a periph- 

 eral groove. It is difficult to understand how such 

 a well-defined structure with a sharply marked limit 

 passing spirally through several layers of sediment can 

 be produced by mechanical means, such as the swirling 

 of water through a hole in the sand. No carbonised 

 remains of vegetable matter have been found adhering 

 to the surface of the Spirophyton impressions, but the 

 same is the case with the undoubted plant impressions, 

 from the Witteberg and Bokkeveld beds in the west of 

 the Colony. 



Whether a true fossil or not, Spirophyton has been 

 found of great service in enabling the Witteberg beds 

 to be recognised, as it is doubtful whether it occurs in 

 the uppermost Bokkeveld beds, and it has never been 

 found in the Dwyka or later rocks. It is met with in 

 hard quartzites and in shales ; the best specimens are 

 those from the quartzites ; the markings are better pre- 

 1 Seward, A. S. A. M., iv., p. 103. 



