514 REPORT— 1893. 



delicate shells have been transported uninjured by ice, this objection be 

 insuperable must be left to the judgment of others. Our own feeling is 

 that if the case depends mainly on this point it is impossible to pronounce 

 upon it with confidence. 



On the whole, our opinion, with all deference, is that we have not yet 

 reached a solution of the difficulties connected with the Clava deposit. 



D. B. 



P. F. K. 



Erratic Blocks of England, Wales, and Ireland. Twenty-first 

 Report of the Committee, consisting of Prof. E. Hull, 

 {Chairman), Prof. J. Prestwich, Dr. H. W. Crosskey, Prof. 

 W. Boyd Dawkins, Prof. T. McK. Hughes, Prof. T. G. Bonney, 

 Mr. C. E. De Range, Mr. P. F. Kendall {Secretary), Mr. K. H. 

 TiDDEMAN, Mr. J. W. WooDALL, and Prof. L. C. Miall. — Draion 

 up by Mr. P. F. Kendall {Secretary). 



The Committee were appointed, as in former years, for the purpose of re- 

 cording the position, height above the sea, lithological characters, size, 

 and origin of the erratic blocks of England, Wales, and Ireland, report- 

 ing other matters of interest connected with the same, and taking measures 

 for their preservation. 



The Committee have again to acknowledge the valuable assistance 

 rendered by the Yorkshire Boulder Committee and the Glacialists' 

 Association, as well as by independent observers. The work of organisa- 

 tion has been prosecuted and several districts are being investigated in a 

 manner that promises to yield results of the highest value. The Corre- 

 sponding Societies have been invited to co-operate, and a hope is enter- 

 tained that information will soon be forthcoming from counties regarding 

 which no reports have as yet been presented to this committee. The 

 President of the British Association, Sir Archibald Geikie, LL.D., 

 F.R.S., has, in his capacity as Director- General of H.M. Geological 

 Survey, granted permission to the officers of his staff to report to the 

 Committee erratics observed during the course of their field-work. A 

 valuable and instructive report by Mr. De Ranee is the first product of 

 this arrangement. The report records every boulder at present visible 

 within the area selected. Similarly exhaustive reports are those by 

 Captain Dwerry house, upon the shores of the estuary of the Mersey, and 

 by Miss Ship ton and Captain Dwerry house, upon the ez-ratics on the 

 Dee shore near Parkgate ; in the latter case the observers have compiled 

 an analysis of their list for publication. 



The comparison of the lists of Messrs. Dambrill-Davies, Piatt, and De 

 Eance on the one hand with those of Mr. Maw by. Captain Dwerryhouse, 

 and Miss Shipton on the other brings out very clearly the much greater 

 relative abundance of Lake District rocks than of those from Scotland, 

 on the eastern side of the plain of Lancashire and Cheshire as compared 

 with the western side of that area. In harmony with this result is the 

 fact that the remarkable list of erratics from the gravels of the Yorkshire 

 Calder contains not a single Scottish rock. 



The Committee regret that they have been obliged to publish merely a 

 digest of their very voluminous report, but arrangements are in progress 



