Mr. D. Sharpe on Secondary Fossils from South Africa. 



201 



depressed above, which gives them a sUght approach to angularity at the middle 

 angle of the spire 75°. 



Length ^ an inch. 



Found in the lowest strata of the Zwartkop crag. 



Ammonites Atherstoni, Sharpe. 



PI. XXIII. fig. 



List of the Fossils from the Sunday and the Zwartkop Rivers. 



[The Sunday River fossils included in the collections presented to the Geological 

 Society are enveloped in a greenish-grey calcareous earthy rock, sometimes a 

 limestone, and often passing into a sand-rock or a grit; green grains are nearly 

 always present, and sometimes in great abundance. 



The fossils from the Zwartkop River district are (excepting the Astarte, Gryphaa, 

 and Ostraa) chiefly casts, often ferruginous, thickly set in a yellowish calcareous 

 rock. For a detailed description of a section of the fossiliferous rocks of the 

 Zwartkop River, see Dr. Krauss's Memoir in the Nova Acta Acad. Ccbs. Leop. Carol. 

 Nat. Cur. vol. xxii. pars 2, 1850, p. 439 ; and Quart. Journ. Geol. Soc. vol. vi. 

 part 2. Miscell. p. 120.] 



Sunday and Zwartkop 



Rivers. 



Ammonites Bainii, Sharpe. PI. XXIII. fig. 2 Sunday River. 



Nautilus, undeterm. (5^ inches in diameter) Sunday River. 



Neritopsis? turbinata, <S/«ar/)e. PI. XXIII. fig. 5 Sunday River. 



Small Gasteropods Sunday River. 



One like fig. 23, PI. XXVIII., and \ inch long; one like fig. 25, 



PL XXVIII., and | inch long; and one like fig. 18, 



PI. XXVIII., and ^ inch long; these are in a greenish grit 



from Sunday River, and are evidently finer individuals of 



the species from " the lowest strata of the Zwartkop crag " 



(see p. 203). 



Ostraea, spp. Single individuals; attached to shells and wood ;1 _, , _,. 



, . \ Sunday River, 



and in mass J 



Gryphaea imbricata, Krauss, sp. [loc. cit. pi. 50. fig. 2.)| Sunday and Zwartkop 

 ni WTTT /!_ ., Rivers. 



Sunday River. 

 Sunday and Zwartkop 



Rivers. 

 Sunday River. 

 Sunday River. 

 Sunday River. 

 Sunday River. 

 Zwartkop River. 

 Sunday River. 

 2 E 2 



PI. XXIII. fig. 3 

 Perna Atherstoni, Sharpe. PI. XXII. fig. 4 . 



Gervillia dentata, Krauss {loc. cit. pi. 50. fig. 1) 



PI. XXII. fig. 1 . 



Pinna Atherstoni, Sharpe 



Lima, sp. (undeterm.) 



Modiola Bainii, Sharpe. PI. XXII. figs. 2 & 3 . 

 Area Atherstoni, Sharpe. PI. XXII. fig. 10 . . 

 CucuUaea? cancellata, Krauss [loc. cit. pi. 48. fig. 2) 

 Trigonia Vau, Sharpe. PI. XXII. fig. 5 . . . 



