498 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



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rated the various fossils I obtained ; 

 and the longer I continued the ex- 

 amination the more I was con- 

 vinced that not much practical good 

 would be effected until not only 

 the fossils from each locality, but 

 also from each particular stratum, 

 had been separately arranged. In 

 this paper I record the results of 

 these observations, imperfect as of 

 necessity they are, doubting not 

 that future investigators, with 

 more lengthened opportunities 

 than I have had myself, will most 

 probably modify some of my con- 

 clusions. 



A. Trlgonia-heds of the Uiten- 

 Tiage Formation. — In following up 

 this subject I shall first treat of 

 the fossiliferous strata of the 

 Zwartkops Eiver, and then of those 

 of the Sundays Eiver. After that 

 I shall proceed to describe the 

 more recent deposits in the neigh- 

 bourhood of the former river and 

 Port Elizabeth. 



Lower Zwartkops River. Section 

 at Roclce's Bluff. — The portion of 

 the Lower Zwartkops River that 

 has been most frequently exa- 

 mined is a part of the heights not 

 far from the mouth of the river, 

 named by the geologists visiting it 

 " Eocke's Bluff," after our friend 

 and fellow-labourer Colonel B,. H. 

 liocke. It is situated about a 

 mile above Bawson's Bridge, on 

 the east bank of the river. Here 

 the lowest fossiliferous band is 

 foimd in an old road, and is 

 marked No. 13 in Section A* and 

 fig. 1 (see also fig. 3). From it Isas- 

 trcea Ricliardsoni f was obtained. 

 The most characteristic fossil of 

 this stratum is Astarte Bronnii. 

 Pleuromya lutraria and Astarte 



* The sections mentioned but not 

 figured in this menioii' are preseryed in 

 MS. in the Society's archives, 



t Quart. Journ. Geol. Soc. sxiii. p. 162. 



