480 Correspondence — R. M. Brydone. 



CORRESPONDENCE. 



EPIASTER AND MICRASTER IN THE WEYBOURN CHALK. 



Sir, — The proportion of E 'piaster to Micraster in the Weybourn 

 Chalk has generally been substantial, and has lately been very 

 marked. Last year I found seven specimens of Epiaster to one 

 Micraster, and their range seems quite limited. It would be very 

 interesting to know if Epiaster is abundant at any other points in 

 the Bel. miicronata Chalk of Norfolk, as a limited horizon 

 characterized by Epiaster and identifiable with the Belgian Craie 

 de Nouvelles might be very useful in correlating isolated exposures. 



Erratics of Weybourn Chalk may account for the Epiaster and 

 Micraster recorded in the Survey Memoir, The Cretaceous Rocks of 

 Britain, vol. iii, pp. 499, 500, and by me in Further Notes on the 

 Stratigraphy and Fauna of the Trimingham Chalk, p. 19, as from 

 Trimingham, where I can still say that I have never seen any trace 

 of an Epiaster or Micraster in situ. The Survey records were probably 

 based, like mine, on Mr. Savin's collection, and m,y recollection of 

 his specimens is that they were distinctly flat. So are those from 

 Weybourn. In 1913 I heard of Micraster being found at Trimingham, 

 and the one I saw was distinctly flat. They seemed to be all traceable 

 to an erratic of Chalk, just above beach-level at a point where it had 

 j)robably foundered from the top of the cliff, and where an erratic 

 has recently become visible at the top of the clifi. 



R. M. Brydone. 



lOth August, 1922. 



ANNOUNCEMENTS AND INQUIRIES. 



In connexion with his work on the Pliocene deposits of Western 

 Cornwall, Mr. H. B. Milner was led to investigate the Aptian sands 

 of Wiltshire as a possible source of material, especially kyanite. 

 He now proposes to extend his study of this formation towards the 

 N.E., as far as Woburn. Mr. Milner is also engaged jointly with 

 Mr. Gr. M. Part on the petrography of the Corallian rocks of South 

 Dorset. 



