372 ' Reports and Proceedings — 



Geological Society of London. 



June 19th, 1895.— Dr. Henry Woodward, F.R.S., President, in 

 the Chair. 



Mr. Whitaker called attention to the two new Survey maps of 

 the Bournemouth district. In the map without Drift it would be 

 olDserved that the boundary-lines were more detailed. In the map 

 with Drift much new work had been incorporated — in fact, the Drift- 

 lines were wholly new. The work had been done by Mr. C. Eeid. 



The following communications were read : — 



1. "On the Occurrence of Radiolaria in Chalk." By W. Hill, 

 Esq., F.G.S., and A. J. Jukes- Browne, Esq., B.A., F.G.S.i 



The authors notice the rarity of records of Cretaceous Eadiolaria, 

 and ^,llude to those which have been made, including those by 

 Eiist and Sollas. They have recently discovered spherical bodies 

 resembling in form and general appearance certain calcified and 

 partially destroyed radiolarian tests from some of the Barbadian 

 rocks ; microscopic examination of these has proved that many of 

 them, at any rate, are Radiolaria. They occur in the nodules of the 

 lower beds of the Melbourn Eock, at Melbourn, Eoyston, near 

 Hitchin, Leagrave near Luton, Pitstone and Tring, Watlington, 

 the Eichmond boring, the lower part of the " Grit Bed " at Dover, 

 Sutton Waldron and Burcombe (Dorset), and in a nodular chalk 

 which may be considered as the equivalent of the Melbourn Eock 

 from Biudon Clifls, near Axmouth, Devon. Similar organisms have 

 recently been found in the Chalk Marl of Lincolnshire, Yorkshire, 

 and Norfolk, but have not been noticed in any other parts of the 

 Chalk. It is suggested that they occurred in many portions of the 

 Chalk-ooze, but were usually i-apidly and completely dissolved, and 

 contributed to that solution of silica which furnished the substance 

 of flint-nodules ; and the authors conclude that the preservation of 

 traces of the Eadiolaria in the nodules of the Melbourn Eock is due 

 to some specially favourable conditions. 



A description of the changes undergone by Barbadian Eadiolaria 

 is given to illustrate the instability of radiolarian tests. Here all 

 stages are traceable, from the perfect siliceous test to a structureless 

 ball or disc filled with calcareous matter, or a mere patch of clear 

 crystalline material. 



A description of forms recognized in the nodules of the Melbourn 

 Eock is given. 



2. " The Crush-Conglomerates of the Isle of Man." By G. W. 

 Lamplugh, Esq., F.G.S. ; with an Appendix by W. W. Watts, Esq., 

 M.A., F.G.S. (Communicated by permission of the Director-General 

 of the Geological Survey.) 



The Skiddaw Slates of the Isle of Man have everywhere under- 

 gone intense shearing, and on the north-west side of the main 

 stratigraphical axis actual disruption of the bedding with the 

 resultant formation of breccia or crush-conglomerate on a large 



' See also paper by Mr. G. E. Grimes on Eadiolarians in the English Chalk, 

 ante, p. 345. 



