282 'Reports and Proceedings. 



brevidens and suhulidens, and the whole section (but chiefly the above 

 and Constitution Hill) has yielded 129 species. The base when seen 

 invariably rests on a grey laminated sandy marl, resting on the 

 Northamptonshire Sands. 



In making a new branch railway recently at G-reatworth, the 

 Great Oolite was found to be eroded and smoothed by glacial action, 

 and filled with drift. The base is a blackish clay, with abundant 

 decayed glacial shells, above is a grey sand with a few shells, over- 

 laid by gravels, clays, and sands, with pebbles and lumps of hard 

 chalk, Permian sandstone, Ostrea dUatata, and Marlstone, mostly 

 scratched. 



Mr. Beesley describes the faults traced in the Geol. Survey Map, 

 and also a small one, parallel with Broughton fault, from Broughton 

 road across the low ground between Constitution and Crouch Hills, 

 with a downthrow north of 30 feet. C. E. De E. 



lasiPOiaTS j^scsTHD :pisoo:bei3Ii<tc3-s. 



Geological Society of London. — I. — March 20, 1872. — Prof. 

 John. Morris, Vice-President, in the Chair. — The following com- 

 munication was read : — " On the Wealden as a Fluvio-lacustrine 

 Formation, and on the relation of the so-called ' Punfield Formation ' 

 to the Wealden and Neocomian." By C. J. A. Meyer, Esq., F.G.S. 



In this paper the author questioned the correctness of assigning 

 the Wealden beds of the south-east of England to the delta of a 

 single river ; he considered it more probable that they are a fluvio- 

 lacustrine rather than a fluvio-marine deposit, and attributed their 

 accumulation to the combined action of several rivers flowing into 

 a wide but shallow lake or inland sea. The evidence adduced in 

 favour of these views was mainly as follows : — The quiet deposition of 

 most of the sedimentary strata, the almost total absence of shingle, 

 the prevalence of such species of Mollusca as delight in nearly qijiet 

 waters, the comparative absence of broken shells such as usually 

 abound in tidal rivers, and the total absence of drift-wood perforated 

 by Mollusca in either the Purbeck or Wealden strata. 



This Wealden lacustrine area the author supposed to have origi- 

 nated in the slow and comparatively local subsidence of a portion of 

 a land-surface just previously elevated. He considered that during 

 the Purbeck and later portion of the Wealden era the waters of such 

 lacustrine area had no direct communication with the ocean. The 

 changes from freshwater to purely marine conditions, which are 

 twice apparent in the Purbeck beds, and the final change from 

 Wealden to Neocomian conditions at the close of the Wealden, were 

 attributed to the sudden intrusion of oceanic waters into an area 

 below sea-level. 



The author then pointed to the traces of terrestrial vegetation in 

 the Lower Greensand as evidence of the continuance of river-action 

 after the close of the Wealden period. 



In the concluding portion of his paper the author referred to the 

 relation of the Punfield beds of Mr. Judd to the Neocomian and 



