1911-12.] 



539 



conclusively that beekite is not limited in occurrence either 

 geographically or stratigraphically. (2) He has brought forward 

 a novel and ingenious theory to account for its origin, in which he 

 postulates three factors — (a) the presence of a calcareous organism, 

 as a nucleus or base, (/>) an attacking force of boring worms, or 

 sponges, and (c) the presence of silica in solution in the water in 

 sufficient quantity to admit of deposition. He also lays stress 

 upon the agency of organic matter in depositing and attracting 

 the silica. He supposes, in brief, that the decomposing animal 

 matter of the organism attracted silica from the sea-water and 

 deposited it on and around the bore-holes formed in the shells, 

 etc., by parasitic and predatory creatures, such as worms, etc. 

 " The process would start as soon as decomposition commenced, 

 therefore Beekite would be formed shortly after the death of the 

 victim, and would probably be a fairly rapid deposit." He also 

 refers to the boring of tenantless shells on the beach by Bryozoa, 

 etc., as taking place after the formation of beekite upon them. 



LATER INVESTIGATIONS. 



The specimens of beekite I have examined were supplied 

 partly by Mr. Wickes and partly by Mr. Robert Bell, who 

 discovered beekite in the Cretaceous of Co. Antrim, and with 

 whom I had the pleasure of procuring many specimens in situ. 



OCCURRENCE. 



With regard to the occurrence of beekite the chief feature 

 that strikes the writer is the fact that it always occurs in porous 

 rocks such as sandstone, limestone and conglomerates. As observed 

 by Wickes it is frequently associated with other deposits of silica, 

 such as flint and chert, which I believe to be contemporaneous in 

 formation with the beekite. It is always associated with marine 

 fossils, and in many cases appreciable quantities of organic matter 

 are present. Even the specimens which appear most free from 

 organic matter yield characteristic odours when ignited. 



