i38 



[Proc. B.N.F.C, 



silica into shells with its penetration between the cleavage surfaces 

 of minerals as analogous phenomena. Remarked the difference, 

 however, between the silicification of calc-spar and shell carbonate 

 of lime, and inferred that the presence of organic matter in the 

 latter, if the amount of organic substances in shells ivere not so 

 small, might play some part in the process. He concluded 

 cautiously that the recognition of the true causes of these 

 differences remained for future investigation. 



Wm. Pengelly : — On the Beekites found in the Red Con- 

 glomerates of Torbay — a paper read before the British Association 

 at Cheltenham, 1856. Described beekite as chalcedony and gave 

 a characteristic description of its appearance and occurrence. 

 Observed that the " tubercles and rings " of chalcedony always 

 surrounded a fossil nucleus. Although the fossil had often 

 disappeared it was often possible to trace its character in the 

 distorted beekite replacement. He theorised that the chalcedony 

 of beekite was a replacement of carbonate of lime caused by water 

 containing silica in solution percolating through conglomerate 

 rocks. 



Church : — Beekite — Philosophical Magazine, Vol. XXIII. , 

 1862. Gave a chemical account of English beekites. His 

 analyses shew Silica 91 to 93 per cent. ; Lime (as silicate) 2-3 ; 

 Iron oxide 2-2.5 : Water 1-2 ; Carbonic acid and Organic Matter 

 1.5-2.5. With regard to its origin he compared the circular 

 disposition of beekite to other forms of silica which have a 

 tendency to develop circular and spherical forms. 



W. H. Wickes \— Beekite— Bristol Nat. Soc, Proa, Vol. II., 

 Part III., 1 9 10. This writer has confirmed many of the 

 observations made by older writers. The chief features of his 

 results are : — (1) the extension of our knowledge of the occurrence 

 of beekite from one or two British localities to numerous localities 

 all over the British Islands, from the Cambrian limestone of 

 Durness in Scotland to the Chalk of Surrey and of Antrim in 

 geological time. He also adds a list of foreign localities, shewing 



