144 SCIENCE PROGRESS 



Fossil Floras 



Much progress has been made in the working out of the 

 fossil floras collected from various British coalfields on the 

 lines laid down by Kidston (25) in his memorable paper " On 

 the various divisions of British Carboniferous rocks as deter- 

 mined by their Fossil Flora," published in 1894. The same 

 author has proposed a new terminology of the various 

 Palaeobotanical Zones in a more recent contribution (33), 

 which has not, however, met with universal acceptance. The 

 following comparison indicates the changes proposed : 



Kidston's Classification of the British Upper Carboni- 

 ferous Rocks 



1894 

 Upper Coal Measures 

 Transition Series 

 Middle Coal Measures 

 Lower Coal Measures 



1905 

 Radstockian 

 Staffordian 

 Westphalian 

 Lanarkian 



The detailed examination of the floras of the British coal 

 basins has not only greatly increased our knowledge of many 

 genera and species but possesses a special interest as a study 

 of the course of evolution of plant life during Carboniferous 

 times. It has also proved extremely valuable from the point 

 of view of the mining engineer and colliery proprietor (1). 



Special attention has been devoted by Kidston (s5) to the 

 floras of the unproductive red measures, bordering the produc- 

 tive measures of several of the Midland coalfields, especially 

 the North Staffordshire, Birmingham, and Denbighshire coal 

 basins. These have proved to belong either to the Upper Coal 

 Measures or to the Transition Series or to both. Similarly, the 

 red shales of the Ardwick Series (2) and part of the Bradford 

 Series (19, 33) of Manchester have been shown to represent the 

 Transition Series. 



The fossil 'floras of part of the Cumberland coalfield, in 

 which red rocks, known as the Whitehaven Sandstone, overlie 

 a dark-coloured shale series containing coals, have also been 

 worked out (3). The floras of both lithological divisions proved 

 to belong to the same horizon, the Middle Coal Measures. 



In regard to the floras of the larger coalfields of the Midlands 



