PKOCEEDINGS OF THE GEOLOGICAL SOCIETY. 3 



Uruguay, was presented to the Museum by A. K. Mackinnon, Esq., 

 F.G.S. ; and four specimens of Mexican Building-stones by F. 

 Newman, Esq., E.G.S. 



The following communications were read : — 



1. " Note on a Wealden Eern, Oleandridium {Tosniopteris) Bey- 

 ricMi, Schenk, new to Britain." By John E. H. Peyton, Esq., 

 P.G.S. 



This fern, figured by Schenk in the ' Palaeontographica ' (vol. xix. 

 plate xxix. figs. 6, 7), was discovered near Minden, in the North- 

 west G-erman Wealden -beds, and appears to have been hitherto 

 unknown in England. It was first discovered in the Wadhurst 

 Clay (" Tilgate stone " of Mantell) of the cliffs east of Hastings, by 

 Mr. Charles Dawson, of Warrior Terrace, St. Leonards, who has a 

 fine collection of Wealden fossils, and was brought to my notice by 

 Professor Augusto de Linares, of the Yalladolid University, who has 

 lately discovered the Wealden in the north of Spain. 



This specimen*, which I have much pleasure in presenting to the 

 Society for their Museum, I found about a fortnight ago, also in our 

 local " blue-stone " from the Wadhurst Clay of the Hastings cliffs. 



In connexion with the flora of the Wealden, I may perhaps 

 mention that, besides the ordinary ferns recorded by Mantell, 

 Eitton, Topley, and others, viz. Lonchopteris ManteUi, Sphenopteris 

 gracilis, S. ManteUi, S. PhiUipsii, S. Sillimani, &c, I have been 

 fortunate enough to discover the following North-German forms : — 



Pecopteris Geinitzii, 



Pecopteris Murchisoni, 



Pterophyllum schaumburgense (Dunker), 



and an undetermined one, which I think is Sphenopteris Gcepperti. 

 They all occur in the beds of stone in the Wadhurst Clay, which are 

 locally used for building and road-metal. 



2. " On the Mechanics of Glaciers, more especially with relation 

 to their Supposed Power of Excavation." By the Bev. A. Irving, 

 M.A., E.G.S. 



A specimen of Oleandridium Beyrichii, Schenk, was exhibited, in 

 illustration of Mr. J. E. H. Peyton's communication. 



* It varies slightly from the one figured by Schenk in the nervures ; and 

 the midrib is " herring-boned." It bears a strong resemblance to Tceniopteris 

 vittata (Brongn.) of the Trias (Geikie's 'Text-Book of Geology,' fig. 358) ; 

 compare also T. scitaminecpfolia (Sternberg), from the Stonesfield beds 

 (Phillips's ' Geology of Oxford,' Diagram xxx. fig. 8). 



