392 Proceedings of the Royal Physical Society. 



contain certain forms in great abundance. The Upper Car- 

 boniferous flora is characterised chiefly by the abundance of 

 Ferns, Calamites, Lepidodendra, Sigillarias, and Oordaites.^ 



Mr Kidston still further divides the Coal-Measures into 

 three groups, each more or less characterised by the greater 

 abundance of certain forms than in the other subdivisions. 

 The Coal-Measures of Scotland he correlates with the lowest 

 of these three subdivisions, and the Bed, or Upper Coal- 

 Measures of Scotland, with his middle zone.^ 



Mr Kirkby, from his study of the Ostracoda, shows that 

 certain forms are restricted to a less thickness of strata than 

 either the fishes or the plants. 



From the evidence obtained from fossils, the late Mr Jas. 

 Thomson, Mr Wiinsch, and other members of the Glasgow 

 Geological Society showed that strata in the island of Arran, 

 which were considered by some as belonging to the Upper 

 Old Red Sandstone formation, are of Lower Carboniferous 

 age. A suite of Plants found in the Locherim Burn, near 

 Corrie, by M. W. Ivison Macadam, was shown by Mr Kid- 

 ston to be of Lower Carboniferous type. During the pro- 

 gress of the Geological Survey in Arran these points were 

 corroborated, and the various subdivisions of the Carboni- 

 ferous system from the Calciferous Sandstones up to the Coal- 

 Measures were mapped in detail by Mr Wm. Gunn,^ and large 

 collections of fossils were made by Messrs Macconochie and 

 Tait. From the study of these fossils it has been proved that 

 strata of Coal-Measure age occur in five or six separate local- 

 ities, thus affording a new point in the geology of the island.* 

 During the progress of the Geological Survey in Argyle- 

 shire, Mr H. Kynaston mapped a small area of red-stained 

 sandstones in the valley of the Awe, near Taynuilt,^ which 

 was first noticed by MaccuUoch. From this a small suite of 

 fossils was obtained by Mr Tait. The Plants were pro- 

 nounced by Mr Kidston to be of Lower Carboniferous type, 



1 R. Kidston, Proc. Roij. Phys. Soc, vol. xii. pp. 183-257, 1884. 



2 R. Kidston, Proc. Roy. Phys. Soc, vol. xii. pp. 183-257, 1884. 



3 Mem. Geol. Sur., "Summary of Progress for 1897," p. 112, 1898. 



* Mem. Geol. Sur., "Summary of Progress for 1897," pp. 113-123, 1898. 

 5 Mem. Geol. Sw:, "Summary of Progress for 1898," p. 129, 1899. 



