Meports and Proceedings — Geological Society of London. 281 



the posterior nares, showing the bifurcated opening with the vomerine 

 element running back almost to the sphenoid, a feature which the 

 author thinks will prove to be common to all species of Metriorhynchus. 



2. " The High-level Platforms of Bodmin Moor, and their Relation 

 to the Deposits of Stream Tin and Wolfram." By George Barrow, 

 F.G.S. (Communicated by permission of the Director of H.M. Geo- 

 logical Survey.) 



In this area there are three platforms — one, which is marine and 

 of Pliocene age, terminating in a steep slope of 430 feet above the sea; 

 a second, at a height of 750 feet, seen about Camelford and at the foot 

 of Delabole Hill ; and a third, a little under 1,000 feet, first recognized 

 on Davidstow Moor. The valleys cutting the lowest platform are 

 found to have been much deepened since the uplift of the platform to 

 its present level ; but the features thus caused gradually die out in 

 the higher part of the valleys, disappearing in the Eiver Camel about 

 22 miles from the sea. At the higher parts of all these platforms, 

 marshes are frequently found. 



The superficial deposits which bear tin above the 750 foot platform 

 differ markedly at times from those below it, as here ancient wash is 

 preserved — possibly protected, by a snowfield or by being frozen, from 

 the denudation which has destroyed them below this level. These 

 deposits are not so concentrated as the stream-sorted material below, 

 but they have been frequently worked in past times until the 

 industry languished, in consequence of the difficulty or impossibility 

 of separating the wolfram contained in the enriched portion of these 

 deposits from the tin-ore. This difiiculty having been overcome, and 

 the wolfram being even more valuable than the tin-ore, the industry is 

 now reviving. The veins from which the wolfram is derived have 

 been found close to the points where the ' wash ' is enriched by their 

 denudation. The method of working is described, and it is shown 

 that the success of it depends to some extent on the slope of the 

 granite floor on which the detritus rests ; otherwise the deposit 

 becomes waterlogged, and the method of separation adopted is ex- 

 pensive to carry out. 



On Bodmin Moor the larger marshes have a floor of kaolinized 

 granite ; but there is a difficulty in working it at many points, in 

 consequence of the waterlogging by peaty water. This difficulty 

 does not exist at Staunon Marsh, which has sloping sides instead of 

 a flat base, the cycle of denudation in this case being incomplete. 



2.— March lUh, 1908.— Professor W. J. Sollas, Sc.D., LL.D., F.B.S., 

 President, in the Chair. 



The following communications were read : — 



1. "The Carboniferous Ptocks at Loughshinny (County Dublin), 

 witb an Account of the Faunal Succession and Correlation." By 

 Charles Alfred Matley, D.Sc, F.G.S., and Arthur Yaughan, B.A., 

 D.Sc, P.G.S. 



After an introduction recalling the succession at Bush, already 

 described by the authors, a detailed account is furnished of the various 



