Vol. 50.] Otf THE PURBECK BEDS OF THE VALE OF WARDOUR. 71 



parried sometimes by the quiet intermixture of marine and fresh- 

 water forms of life. As the lagoons communicated with one and 

 the same sea, it is not surprising that nearly similar conditions of 

 strata and of fossils should be found to exist, in approximately 

 uniform succession, wherever tho Pnrbecks are now opened out. 



The genus Cypridea occurs throughout the Purbeck series, and 

 has an ally now living in the Lake of Geneva. That tho leading 

 species in the Upper Pnrbeck (Cypridea punctata) is closely allied 

 to the next following form (G. valdensis, of the Wealden Beds) 

 there is no doubt ; but it is distinct. The finding of Eadogenites erosa 

 in place in the Wardour Pnrbeck clears up some doubts about the 

 relics of that fossil having been found near Hartwell, Bucks. 



Mr. H. B. Woodward remarked that in his original section at 

 Diuton (Quart. Journ. Geol. Hoc. vol. xxxvii. 1881, p. 25 L) 

 Mr. Andrews had taken the Wealden boundary at a lower level, 

 and had considered that the Upper Purbeck Beds were absent. He 

 was inclined, however, to agree in part with that interpretation of 

 the section, believing that the coloured clays and sands with Endo- 

 genites should be classed as Wealden. Even on this view there was 

 no evidence to show that Upper Purbeck Beds were unrepresented. 

 He had no faith in fixing a plane of demarcation between the 

 Purbeck and Wealden Beds by means of ostracoda. 

 ' By permission of the President, he read extracts from a letter of 

 the Rev. P. B. Brodie, who desired to state that " When I first 

 visited, the Vale of Wardour there were but few available sections, 

 and, as a young geologist, I naturally followed the lead of so able a 

 one as Dr. Pitton. All this was more than half a century ago. 

 Since then Mr. Andrews' fortunate residence in the district, and the 

 fine section exposed in the railway-cutting near Teffont, has enabled 

 him and Mr. Jukes-Browne to study far better sections than either 

 Pitton or myself had seen, and hence their decision is no doubt 

 correct as to the stratigraphical divisions which they now propose." 



After alluding to the interesting paper by the President (1881) in 

 connexion with an excursion of the Geologists' Association, Mr. Wood- 

 ward observed that the pre-Cretaceous folds in the Purbeck and 

 Portland Beds, to which the Authors had drawn attention, might be 

 compared with those affecting the Jurassic rocks in the Weymouth 

 and Purbeck area, which Mr. Strahan had lately interpreted in 

 carrying out the Government geological survey. 



The Bev. W. R. Andrews, in reply, said that the threefold 

 division of the Purbeck by Porbes, based on the ostracoda, had 

 been fully borne out by the investigations of Prof. T. Rupert Jones. 

 The yellow Wealden Clay overlies the Upper Purbeck, but does not 

 always rest on the same bed. This the speaker explained by pre- 

 Cretaceous earth-movements. He thanked the Society, on his own 

 behalf and on that of his colleague, for the manner in which their 

 paper had been received. 



