^ 



No. 419. New Series.— Decade IV.— Vol. VI.— No. V. Price Is. 6d. nett. 



THE 



GEOLOGICAL MAGAZINE 



OCT X mo 



0ntIU|) Jauiinal of (Btoh^h 



WITH WHICH IS INCORPORATED 



TME GEOLOGHST." 



EDITED «Y 



HENRY WOODWARD, LL.D., F.R.S., F.G.S., &c. 



ASSISTED BY 



ROBERT ETHERIDGE, F.R.S. L. & E., F.G.S., &c., 



WILFRID H. HUDLESTON, M.A., F.R.S., F.L.S., F.G.S., &,c., 



GEORGE J. HINDE, Ph.D., F.R.S. , F.G.S., Soc, and 



HORACE BOLINGBROKE WOODWARD, F.R.S., F.G.S. 



MAY, 1899. 



OOnSTTZBHSTTS 



Frontispiece: Portrait of Prof. 

 0. C. Marsh. 

 I. Original Articles. 



1. Note on a New Australian 

 Pterygotus. By Professor Sir 

 F. McCoy, K.C.M.G., D.Sc, 

 F.E.S. (With a Process-block.) 193 



2. AUanite in the Granite of Lairg, 

 Sutherlandshire. By Lieut. - 

 Gen. C. A. McMahon, F.R.S. 194 



3. Glaciated Valleys in the Cuillins, 

 Skye. By Alfred Harker, 

 M.A., F.G.S., of H.M. Geo- 

 logical Survey of Scotland. 

 (With four Woodcuts.) 196 



4. Notes on some Marine Miocene 

 Shells fi-oni Egypt. By R. 

 BuLLEN Newton, F.G.S. 

 (Plates VIII and IX.) 199 



5. Zones and ' Chronological ' 

 Maps. By A. J. Jukes-Browne, 

 B.A., F.G.S 216 



6. On the Average Composition of 

 British Igneous Rocks. By 

 Alfred Harker, M.A., 

 F.G.S., Fellow of St. John's 

 College, Cambridge 220 



Original Articles — continued. page 



7. On the Dates of the <'Paleon- 

 tologie Francjaise " of D'Orbigny. 

 By C. Davies Sherborn 223 



II. Notices of Memoirs. 



The Drift or Glacial Deposits 

 of Ayrshire. By John Smith... 225 



III. Reviews. 



A Supposed Existing Ground- 

 sloth in Patagonia 226 



IV. Reports and Proceedings. 



Geological Society of London — 



1. February 22, 1899 228 



2. March 8, 1899 230 



V. Coruespondence. 



1. Mr. G. H. Morton, F.G.S. .,. 231 



2. Professor Edward Hull, F.R.S. 232 



3. Mr. A. J. Jukes-Browne, F.G.S. 234 



VI. Obituary. 



1. The Rev. J. D. La Touche 235 



2. Professor 0. C. Marsh. (With 



a Portrait.) 237 



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