Reports and Proceedings — Geological Society of London. 141 



A record is given of some of the earliest known foraminifera, 

 including the somewhat doubtful forms described by Cayeux from 

 pre-Cambrian rocks in Brittany, those b}' Ehrenberg from the so- 

 called ' Silurian Clay ' near St. Petersburg, by W. D. & G. F. 

 Matthew from the rocks bearing the Protolenus - fauna in New 

 Brunswick, by Keeping from the shells above the Bala Limestone 

 near Welshpool, by Blake from the Llandovery of Cwm Symlog, 

 by Brady from the Woolhope Limestone of the Malverns, and by 

 Terquem from the Upper Silurian rocks of Indiana. The author 

 has also frequently met with Lagena in the Wenlock Limestone of 

 Shropshire. 



2. "Bala Lake and the River -System of North Wales." By 

 Philip Lake, M.A., F.G.S. 



In this paper the author begins by showing that topographically 

 Bala Lake belongs to the same valley as the River Wnion — the 

 valley of the Bala Fault ; and he believes that the whole drainage 

 of the valley flowed originally south-westward, and entered the sea 

 near Barmouth. 



He then examines the possible outlets, and shows that the lake 

 is probably rock-bound in all directions except towards the south- 

 west, where there is no conclusive evidence. 



He describes the faults which occur near the watershed that 

 separates the Wnion from the streams flowing into Bala Lake, 

 pointing out that they are closely related to the form of the valle}'. 

 and that the watershed coincides with a transverse line of fault. 

 From this he infers that the formation of the lake is possibly due to 

 earth-movements. 



The watersheds of several other similar valleys are examined, 

 and are shown to lie in one straight line ; whence it is concluded 

 that they must have been produced by some general cause, probably 

 a slight differential movement. 



The general drainage-system of North Wales is next discussed. 

 Attention is drawn to the existence of a series of long and nearly 

 parallel valleys running from north-east to south-west, which divide 

 the region more or less completely into a number of strips. The 

 drainage of each strip is now independent, and flows in most cases 

 into the long valley lying south of it. But from the fact that the 

 chief streams in each strip have their representatives (flowing in 

 the same line) in the adjacent strips, it is concluded that before the 

 formation of the long valleys the streams were continuous. 



The centre from which these streams radiate lies in the high 

 ground near the sources of the Conway ; and the author believes 

 that this was the centre of an original radial system of drainage, and 

 that this radial system was subsequently broken up into sections by 

 the formation of the long valleys which now run from north-east to 

 south-west — each of these long valleys carrying away the drainage 

 of one of the sections. He attributes the formation of the long 

 valleys to faulting. 



