Reports & Proceedings — Geological Society of London. 91 



The group is by far the most characteristic of all the plants of the 

 Jurassic and Lower Cretaceous, during which periods its distribution 

 was almost world-wide. It was locally, if not universally, dominant, 

 and was the most highly evolved plant-group of the epoch of which 

 we are cognizant. 



Three chief points of interest are to be noted in the geological 

 distribution of these plants : (a) that the most numerous highly 

 specialized trunks reach their maximum in the Jurassic and Lower 

 Cretaceous Periods, when their distribution was practically world- 

 wide ; (h) that the oldest and therefore presumably the most primitive 

 type, Wielandiella, is externally less like the living Cycads than the 

 commoner later forms, while these latter are utterly unlike the living 

 genera in their fructifications; (c) that the geologically youngest 

 cone is the largest yet discovered, occurring in the Gault when the 

 extinction of the group appears already to have set in. 



Contrary to what might have been anticipated from their external 

 likeness to the living Cycads, coupled with their great geological age, 

 the fossil ' Cycads ' are much more complex and on a higher level of 

 evolution than the living group. It seems to the author to be 

 extremely unlikely that the fossil and the living forms have any 

 direct phylogenetic connexion nearer than a remote, unknown, 

 common ancestor. The mooted connexion between the fossil ' Cycads ' 

 and the Angiosperms is highly suggestive, but lacks data for its 

 establishment. 



A short discussion followed, and the thanks of the Fellows present 

 wei'e accorded to Dr. Stopes for her lecture. 



2. January 10, 1917. — Dr. Alfred Harker, F.B.S., President, in the 



Chair. 



The following communications were read : — 



1. "On the Palaeozoic Platform between the London Basin and 

 Adjoining Areas, and on the Disposition of the Mesozoic Strata upon 

 it." By Herbert Arthur Baker, B.Sc, F.G.S. With an Appendix 

 by Arthur Morley Davies, D.Sc, F.G.S. 



The author carries on the work of Dr. A. Strahan and Dr. Morley 

 Davies in tracing the contours of the Palaeozoic platform of the 

 South -East of England. By comparing these with the contours of 

 the base of the Gault, he determines the probable boundaries of the 

 areas of the platform that were only submerged finally under the 

 Gault sea. He analyses the effects of post-Cretaceous tilting and 

 warping, and presents a map illustrating the contours of the Palaeo- 

 zoic floor at the end of the Lower Cretaceous Period. 



He next discusses the successive Mesozoic overlaps on the platform, 

 the probable areas that they respectively cover, and the relation of 

 these to the tectonics of the platform itself. He claims that there 

 is evidence for a second Charnian axis, parallel to that traced by 

 Professor P. F. Kendall, proceeding south-eastwards through Norfolk 

 and Suffolk, east of Kent, to the North of France. He further 

 suggests that the area between these two geo-anticlines is a geo- 

 syncline, which in Mesozoic times, in consequence of the accumulation 



