442 Scientific Intelligence. — Geology. 



and forty species of infusoria ; with these are a few conferva; 

 and other minute vegetables. The chalk of the south of Eu- 

 rope is without flints, but full of siliceous infusoria, whilst in 

 the chalk of northern Europe there are abundant flinty no- 

 dules, but no siliceous infusoria, except in these nodules, as 

 if they had been attracted to the nascent nodules from the 

 fluid in which they floated. Dr Buckland noticed also the re- 

 cent discovery by Mr Bowerbank of spicula, and of organic 

 cellular and tubular structure, which he refers to parasitic 

 spunges in the black substance of chalk-flints, which often in- 

 closes also alcyonic bodies and shells. Admitting, with Pro- 

 fessor Ehrenberg and Mr Bowerbank, the large contribution 

 which animal remains have supplied to the substance both of 

 chalk and flint, Dr Buckland would refer the earthy portions 

 of the chalk and the inorganic substance of the flint to segre- 

 gation from the waters in which both the lime and flint were 

 held in solution. To a similar segregation from water he 

 would likewise assign the origin of the calcareous earthy ma- 

 trix which invests the calcareous exuviae of molluscous and 

 radiated animals in the shelly, the encrinal, and coralline lime- 

 stones of the silurian, Devonian, and carboniferous series, and 

 which is still more obviously loaded with organic remains in 

 the forest marble and coralline beds of the oolite formation 

 and also in the calcaire grossier, the crag, and fahluns of the 

 tertiary series. Dr Buckland next shewed the relations of the 

 recent nautilus, sepia, and velella to the minute molluscous 

 constructors both of recent and fossil foraminiferous micro- 

 scopic shells, and stated how much the modern discoveries of 

 microscopic shells and infusoria have added to the amount 

 of animal remains that are known to have contributed to 

 the formation of limestone. He illustrated the extent to 

 which molluscous animals occur in our present seas by Cap- 

 tain Beaver's discovery, that two shoals marked in the charts 

 as sand-banks, between the Cape of Good Hope and Mau- 

 ritius, in Lat. 34° 30' S., Long. 27° 30' E., are dense masses 

 of small medusae, floating in water more than 150 fathoms 

 deep ; and, by Captain Scoresby's calculation of the number 

 of medusa? in a cubic foot of water in the Greenland seas, ex- 

 ceeding 100,000. He also stated that the luminous appear- 



