190 Correspondence — Mr. A. C. 8eivard. 



have been transported, more of them than we imagine may be so ; 

 that therefore they do not necessarily indicate former levels of 

 the sea; and that ewerj case is to be judged of by its own evidence. 



As regards Chapelhall, I certainly pointed out the slender 

 evidence on which it rested, it being, so far as I know, quite 

 exceptional in this respect ; but I may say, on behalf of all the 

 Committee, that it was a disappointment to them that the shelly 

 clay was not found ; for it was hoped that a careful examination 

 of it would throw liglit on its origin and mode of formation. 

 This would have been much more satisfactory to them than not 

 finding it at all. 



But Mr. Mellard Reade makes a far more important mistake 

 than any regarding the purport of my poor papers. Referring 

 to the suggestion that the Ayrshire beds have been laid down 

 by a Frith of Clyde glacier, he says — "I can only point out 

 that the hypothetical course of such a glacier does not correspond 

 with that of any map I have yet seen which professes to give 

 the lines of glacial flow in Scotland." Now, this is a point which 

 should be easily settled. I suppose that the two best, most recent, 

 and most authoritative maps of the ice-flow in Scotland are those 

 by the Messrs. Geikie — Sir Archibald's sketch-map in his " Scenery 

 of Scotland," 2nd edition, p. 248 ; and Professor James Geikie's of 

 the British Isles in his " Great Ice Age," 3rd edition, p. 69. Both 

 of these maps distinctly show the lines of ice-flow extending from 

 the mountainous region around the heads of Loch Lomond, Loch 

 Long, etc., across the opening of the Frith of Clyde, over the 

 low grounds of Renfrewshire and Ayrshire, and curving out to 

 sea in the neighbourhood of Ayr, as the West Highland ice came 

 into contact with the ice from the Southern Uplands. And Sir 

 Archibald Geikie expressly says, referring to the striations along 

 the estuary of the Clyde — " These markings prove that the mass 

 of ice moved southward from Loch Lomond, crossed the Clyde, 

 passed over the hills of Renfrewshire, and crept down into the 

 heart of Ayrshire, where it united with the ice that was streaming 

 northward from the Southern Uplands" ("Scenery of Scotland," 

 2nd edition, p. 246). Professor James Geikie also notices the 

 trend of the ice-markings in the lower reaches of the Clyde in 

 similar terms " (Great Ice Age," 3rd edition, pp. 69, 70). 



Now, will Mr. Mellard Reade kindly say what maps he has 

 seen, " professing to give the lines of glacial flow in Scotland," 

 which show them differently from the above? We may then 

 come to understand how he does not appear to have seen Messrs. 

 Geikies' maps, nor I those to which he refers. 



Glasgow, March 8, 1897. DuGALD Bell. 



CYCAJDEOIBEA GIGANTEA, SEWAED : AN OMISSION. 



Sir, — May I make use of j'^our Magazine for the purpose of 

 pointing out an unfortunate omission in a recent paper on a new 

 Cycadean stem from Portland. In the last number of the Quarterly 

 Journal of the Geological Society I gave a description of the 



