No. 674. 



Vol. LVII of Whole Series. 



Price 2s. 6d. 



The 



oiogicai lYiagazine 



fIDoittbh) 3ournal of (Beoloop. 



WITH WHICH:- IS INCOKPOUATED 



THE GEOLOGIST, 



EDITED BY 



HENKY WOODWARD, :^1j 



AND 



R. H. RASTALL, Ivl^^nell^iiS^'^' 



'Mf'l 1920 



JS&ISTEI) BY 



Pkof. .1. AV. GREGORY, D.Sc. F.R.S. ^ Sir JETHRO -T. H. TEALT^, Sc.D., F.R.S. 

 P. H. HATCH, Ph.D., M.Inst.M.M. ,.^.,_P.jio.f. W. W. WATTS, Sc.D., E'.R.S. 



Prop. J. E. MARR, Sc.D., F.R.S. HENRY WOODS, M.A., F.R.S. 



Dr. A.SMITH WOODWARD, F.R.S. 



AUGUST, 1920. 



CONTENTS :- 



Editorial Notes. 



Page 

 .. 337 



Original Articles. 



Beerbachite at the Lizard. By 

 Prof. T. G. BONNEY, F.E.S. ... 339 



Notes on the Fauna of the Lower 

 Devonian Beds of Torquay. 

 By F. K. CowPER Eeed. {Con- 

 cluded.) 341 



The Geology of Castle-an-Dinas 

 Wolfram Mine. Bj E. H. 

 Davison, B.Sc. (With 2 Text- 

 figures.) 347 



On Jurassic Ammonites from East 

 Africa, collected by Prof. J. W. 

 Gregory. By L. F. Spath. 

 (Concluded.) 351 



Investigation of the Mechanical 

 Constitution of Loose Arenaceous 

 Sediments by the method of 

 Elutriation. By H. A. Baker. 

 (With a Text-fig.) {Continued.) 363 



Page 

 Keviews. 



Echinoid or Crinoid ? 371 



Palaeozoic Tillites of Northern 



Norway 372 



The Arbouin Mines, Queensland... 374 



The Kent Coalfield 375 



The Submerged Forest at Bombay 376 



The Porto Eico Earthquake of 1918 377 



Minerals from Bihar and Orissa ... 377 



Arsenic and Antimony Ores 378 



Eepoets and Proceedings. 



Mineralogical Society 379 



Geologists' Association 380 



Correspondence . 



Professor W. M, Davis 381 



W. B. Wright 382 



C. Carus-Wilson 384 



Obituary. 



George Sweet 384 



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