Prof. A. C. Ramsay on the Glacial Theory of Lake -Basins. 289 



living genera in African and American rivers, is he prepared to 

 follow Mr. Godwin- Austen's opinion, that much of the Old Red 

 Sandstone, as distinct from Devonian rocks, is a lacustrine de- 

 posit ? With respect to the Coal-measure strata, constant refer- 

 ence is made in the ' Elements' to their formation in deltas 

 or lagoons ; but no mention is made of great deep inland lakes. 

 Indeed the word lake is only once used in the description of this 

 formation, and it is immediately qualified by the word lagoon. 

 Has any one yet described Permian lakes? though I believe 

 they will be found. And even in his account of rock-salt, Sir 

 Charles does not assert that the salt of the Trias was formed 

 in far inland continental lakes supersaturated with salt, though 

 he refers to those of Asia ; and he again insists rather on la- 

 goons, as in the Runn of Cutch or the Bahr Assal, near the 

 Abyssinian frontier, or the possibility of salt now forming in the 

 Red Sea. Are there any Liassic, Oolitic, or Cretaceous lakes de- 

 scribed ? On the contrary, all their freshwater formations are 

 either said to be deltoid, or the manner of their formation is left 

 in the dark. It is true that lakes have been described of very 

 late Eocene (?) and of Miocene age; and there the record of them 

 begins and ends till we come to post-pliocene and recent times. 

 It is therefore by no means yet a piece of common knowledge 

 " that there are lacustrine deposits of all geological epochs/' 



But if " lacustrine deposits" are " of all geological epochs," 

 has no one spoken of "the agency of ice" in past times? or 

 has no one written of anything that might suggest that idea to 

 an unbiased mind ? Let us look to this. Mr. John Carrick 

 Moore has described conglomerates in the Lower Silurian rocks 

 of Wigtonshire, which might well be called boulder-beds ; for a 

 prodigious number of the enclosed masses of gneiss and granite 

 (which Mr. Moore has pointed out to me on the ground) range 

 from a foot up even to six feet in diameter, and all of them have 

 been derived from ancient strata (perhaps Laurentian) of a region 

 now unknown. 



The conglomerate of the Old Red Sandstone of several parts of 

 Scotland and the North of England is so like the " Upper 

 boulder-di ift " of many parts of Britain, though consolidated, 

 that other geologists besides myself have spent hours in search- 

 ing it for scratched stones ; but, for chemical reasons connected 

 with pressure, which Mr. Sorby will appreciate, none have yet 

 been found, if they ever existed there*. 



Mr. Godwin-Austen has been so bold as to attribute the 

 transport of blocks in the French carboniferous rocks to floating 

 ice ; and I invite any one to examine the ice-scratched erratics 



* The Rev. J. G. dimming long ago suggested the glacial origin of the 

 Old Red conglomerates of the Isle of Man. 



