process-blocks and other illustrative figures. xt 



Page 

 Figs. 4 & 5. Maps illustrating the occurrence of orthoclase and pla- 



gioclase (St. Austell Granite) 556 



6-9. Maps illustrating occurrence of micas, topaz, fluorite, etc. 



(St. Austell Granite) 558 



Fig. 10. Mineral-variation diagram on a ' space-base ' across the 



St. Austell granite-mass 570 



11. Map embodying a summary of gravitative mineral distri- 

 bution (St. Austell Granite) 572 



1. Sketch-map of Ceylon and the adjacent part of India ... 578 

 Figs. 2 & 3. Spondylus waylandi sp. nov 594 



4 & 5. Oslrea virlcti Deshayes 597 



6 & 7. Do. do 598 



1 & 2. Section of the West Cliff and plan of the foreshore at 



Clacton-on-Sea 610 



Fig. 1. Cratcegus clactoncnsis sp. nov 621 



2. Crataegus reidii sp. nov (i22 



3. Crataegus pjjracaniha 622 



Dates of Issue of the Quarterly Journal for 1923. 



No. 313— April 11th, 1923. 

 No. 314— July 6th, 1923. 

 No. 315— Septemb 3 r 22nd, 1923. 

 No. 316— December 29th, 1923. 



Erratum. 



Footnote 1, p. 13. For ' post-Miocene ', read ' Miocene or post-Miocene ' 



