SECTIONAL TRANSACTIONS.— C 355 



non-marine fauna (failure of Carbonicola and Naiadites ; dominance of 

 Anthraconauta in the meagre fauna of the Barren Red Measures). The 

 only possible palseontological partition of the Scottish Productive Coal 

 Measures (i.e. between Skipsey's Marine Band and the Millstone Grit) 

 is afforded by mussel zones (and subzones) and by the floral zones recently 

 worked out in South Wales and England. 



Dr. D. A. Wray. 



There is a remarkably close similarity in the succession of the lower part 

 of the Coal Measures in each of the Pennine coalfields, and in 1929 the 

 writer published a detailed correlation of these measures based largely on 

 general lithological comparisons. In the Main Productive and higher 

 Coal Measures such data are insufficient, and consequently the faunal and 

 floral successions are of prime importance. 



The persistence of very occasional and comparatively thin marine bands 

 over wide areas has been much used, though their value has been con- 

 siderably enhanced by the studies of the non-marine faunal succession. 

 The striking value of the latter was recently revealed in East Yorkshire, 

 where lithological comparisons failed completely ; yet by means of the 

 non-marine shells it was possible to indicate the presence of a complete 

 though greatly attenuated succession of the Main Productive measures as 

 far east as the Trent valley. 



, The floral succession has not hitherto proved of the same value. In 

 Northern France, however, an intensive study of the succession of plant life 

 by Bertrand and others has led to the establishment of a zonal system of 

 considerable precision and refinement. Its application to the succession 

 in this country by Dr. Dix appears to be yielding promising results. 



In 1922, Theissen and his co-workers in America pointed out that indi- 

 vidual coal seams had a characteristic spore-content and suggested its 

 employment as a basis of correlation. Attempts have been made to extend 

 this work to Britain, and, if combined with the stratigraphical data already 

 available, it may prove of considerable value in instituting more precise 

 correlations between detached areas of Coal Measures. 



Mr. S. G. Clift. 



The attack by Dr. Wright on the validity of non-marine lamellibranch 

 zones savours of sabotage and is particularly surprising since he is mainly 

 responsible for the further attempted delimitation of subzones, in the 

 Lancashire Measures, based on characteristic ' mussels ' which he has 

 named. 



Moreover some of these species are known to have a similarly limited range 

 and to occur at corresponding horizons in the zones of the measures of 

 Nottinghamshire and Derbyshire and they maintain their position even in 

 the Scottish fields. 



Further investigation in Notts and Derby has shown that the upper 

 and lower limits of the modiolaris zone can each be determined within a 

 few feet and evidence of the value of ' mussels ' in the zoning of that field 

 will be available at the next meeting of the Association at Nottingham. 



Dr. J. O'N. Millott and Mr. J. J. Walker. 



Dr. Raistrick's seam correlation methods have been used in the Fuel 

 Research Coal Survey Laboratories at Sheffield and at Stoke-on-Trent. 



