THE CRETACEOUS SYSTEM 309 



which are themselves false bedded. Such sections show 

 that the sediments were deposited in water in which 

 strong and varying currents prevailed. Much of the 

 Heidelberg outlier, however, is composed of thin-bedded 

 shales and mudstones, which must have been laid down 

 in quiet water, although thin pebble beds are frequently 

 found with these fine-grained sediments. The outlier 

 is certainly basin-shaped, and no connection has been 

 traced with the Mossel Bay beds to the east, or with 

 the Swellendam basin to the west. It is probable that 

 subsequent earth-movements have disconnected these 

 basins of Uitenhage beds, aided of course by denudation, 

 which has swept away perhaps the greater parts of the 

 Uitenhage beds deposited in that part of the Colony. 



The Heidelberg beds consist chiefly of conglomerates, 

 sands, red and grey mudstones, shales and clays ; near 

 Heidelberg there are some peculiar hard white argilla- 

 ceous beds, which are quarried for foundation-stones, 

 and with them some pale siliceous shales crowded with 

 the thin shells of an entomostracan, Estheria anomala 

 (Kupert- Jones), a fossil that is found at many other 

 places in the Heidelberg outlier, but hitherto not known 

 from the Uitenhage district, or from any of the other 

 outliers of the Uitenhage series. At Heidelberg village 

 the clays exposed by the excavations for the railway 

 station contain the Estheria anomala and another ento- 

 mostracan genus, probably Cypris ; some badly preserved 

 lamellibranch shells closely resembling Unio uitenhagensis 

 of the Uitenhage district have been found in the same 

 beds. Some fish scales belonging to a ganoid genus, 

 some indeterminable plant remains, and a wing case of 



