THK CRETACEOUS SYSTEM 303 



level than the conglomerates exposed within a few 

 miles to the north, east and west, but on account of 

 the strata being to a great extent hidden by soil and 

 alluvium the relation of the two types of deposit is not 

 yet known. 



Along the Bitou River there is a great mass of con- 

 glomerates and loose sandy beds with pockets of lignite. 

 The conglomeratic beds in the Bitou basin are peculiar 

 in that the included fragments of rock are angular in- 

 stead of being well rounded as is usually the case with 

 the pebbles in the Uitenhage conglomerates. The third 

 basin is in the valley of the Pisang River ; the beds in 

 it are less conglomeratic and more sandy and clayey 

 than those of the other two areas, and some of the beds 

 are quartzitic owing to the deposition of silica between 

 the grains of the rock. Near Seal Point casts of Tri- 

 cjonia conocardiiformis have been found in the sandstones 

 and conglomerates. This is the only marine fossil yet 

 found in the conglomerates of the Enon type, but as 

 it is a very characteristic member of the fauna of the 

 Sunday's River beds its occurrence is of great interest. 

 It is evident that the water in which the Pisang River 

 beds were deposited must have been salt, or at least so 

 near the sea that the shells of the dead bivalves could 

 be washed back into it by strong tides. But the ab- 

 sence of marine fossils from the bulk of the Knysna 

 conglomerates and sandstones can only be interpreted 

 on the supposition that the rocks were laid down in 

 water sufficiently far removed from arms of the sea to 

 be free of marine inhabitants. 



The occurrence, which has been already mentioned, 



