84 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 12, 



Lonchopteris Mantelli Brongn Wealden and Lower 



Grreensand. 



„ rugosa Brongn ? 



Phlebopteris contigna Lindl. ^ITutton.Ooliie. 



Sagenopteris cuneata Lindl. 6f Hutton.Oo^ie. 



„ Phillipsii Sternh Oolite. 



Thaumatopteris Muensteri .... Goepp Lias. 



Woodwardites acutilobus .... Goepp Coal-measures. 



„ Muensterianus . .Braun Brown-coal. 



„ obtusilobus .... Goepp Coal-measures. 



? Eobertsi Morris Coal-measures. 



May 12, 1858. 



Walter Jauncey, Esq., Birmingham, and Edmund Cavell, Esq., 

 Saxmundham, were elected Fellows. 



The following communications were read : — 



1. On some of the Glacial Phenomena of Canada and of the North- 

 EASTEEN Peovinces of the United States during the Deift- 

 Peeiod. By Professor A. C. Eamsay, F.R.S., F.G.S. 



[The pubHcation of this Paper is unavoidably deferred.] 



2. On Lamination and Cleavage occasioned by the Mutual Eeic- 

 TiON of the Paeticles of Eocks while in Ieeegulae Motion. 

 By G. PouLETT ScEOPE, Esq., M.P., E.E.S., E.G.S. 



(This paper was withdrawn by the permission of the Council.) 

 [Abstract.] 



The author referred to a former paper read by him before the 

 Society in April 1856, in which this subject was touched upon, and 

 proposed to carry on the inquiry as to the probable effect, upon the 

 internal structure of roclis, of the mutual friction of their com- 

 ponent parts, when forced into motion under extreme and irregular 

 pressures. He commenced by examining the laws that determine 

 the internal motions of substances possessing a more or less imper- 

 fect liquidity, whether homogeneous, or consisting of solid particles 

 suspended in, mixed with, or lubricated by any liquid, under un- 

 equal pressures ; and showed that unequal rates of motion must 

 result in the different parts of the substance, and that in the latter 

 case there will be more or less separation of the solid and coarser 

 from the finer and liquid particles into different zones or layers, 

 those composed of the former moving less readily than those com- 



