rated the various fossils I obtained ; and the longer I continued the examination the more I was convinced 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 conclusions.
A. Trigonia-beds of the Uitenhage Formation. — In following up this subject I shall first treat of the fossiliferous strata of the Zwartkops River, and then of those of the Sundays River. After that I shall proceed to describe the more recent deposits in the neighbourhood of the former river and Port Elizabeth.
Lower Zwartkops River. Section at Roche's Bluff. — The portion of the Lower Zwartkops River that has been most frequently examined is a part of the heights not far from the mouth of the river, named by the geologists visiting it " Roche's Bluff," after our friend and fellow-labourer Colonel R. H. Rocke. It is situated about a mile above Rawson's Bridge, on the east bank of the river. Here the lowest fossiliferous band is found in an old road, and is marked No. 13 in Section A* and fig. 1 (see also fig. 3). From it Isastroea Richardsoni† was obtained. The most characteristic fossil of this stratum is Astarte Bronnii. Pleuromya lutraria and Astarte
- The sections mentioned but not
figured in this memoir are preserved in MS. in the Society's archives.
† Quart. Journ. Geol. Soc. xxiii. p. 162.
Fig. 1.-Collated Sections on the Zwartkops River. (Section D of the Author.)
No. 9. Trigonia-bed. No. 10. Ammonite- and Trigonia-herzogii-bed. No. 11. Cuculloea-Kraussii-bed. No. 13. Astarte-Bronnii-Bed.
