THE RIVER GRAVELS BETWEEN PENRITH AND WINDSOR. 249 



The best specimen so far found, from the Carboniferous 

 of Scotland, was figured by R. Etheridge, junr., 1 who has 

 also described a specimen of C. inomata from the Upper 

 Marine Series at Farley. 2 But no specimen yet recorded 

 sliows the remarkable infolding of the four walls here 

 figured. It seems probable that in the future as the aper- 

 tures of other species become known, they will show other 

 marked differences, and prove to be characters of specific 

 value. 



THE RIVER GRAVELS BETWEEN PENRITH AND 



WINDSOR. 



By H. I. Jensen, d.sc, 



[Read before the Royal Society of N. 8. Wales, October 4, 1911.] 



For many years past Sydney geologists have been well 

 acquainted with the river gravels in the railway cutting 

 near Glenbrook. These gravels have been described by 

 Professor David in his Anniversary Address in 1896 before 

 this Society, and they were also referred to in his paper on 

 the Kurrajong Fault. 3 In the above mentioned address 

 reference is also made to Pleistocene and recent alluvials 

 consisting of river gravels and red sandy soil extending 

 along a length of 20 miles from Mulgoa to Richmond. 

 Professor David clearly included in this series only the 

 alluvials up to 20 feet above present high flood mark. 

 The Glenbrook gravels he regards as older Tertiary or 



1 Geological Magazine. 1873. p, 295. 



2 Proc. Linn. Soc. of N.S.W., Vol. xx, p. 751, f. 1, 1889. 



3 Proc. Eoy. Soc. N.S. W ., December, 1902. 



