458 Proceedings of Philosophical Societies. [June, 



GEOLOGICAL SOCIETY. 



Feb. 20. — The reading of Mr. Parkinson's paper, on the fossils 

 found from the east of Dover to Folkestone, was concluded. 



The author in describing these fossils, adopts Mr. Phillips's 

 division of the beds in which they were found: 



Into chalk, with numerous flints. 



interspersed flints. 



few flints. 



without flints. 



Grey chalk, without flints. 



Blue marl. 



Before he enters on his description of the fossils, the author 

 takes occasion to correct an opinion he expressed in a former 

 communication to the Society, that the gravel round London was 

 originally deposited in the spots which it now occupies. Fur- 

 ther inquiry has satisfied him that it has been derived from the 

 disintegration of the chalk. It is not the author's intention to 

 enter into an enumeration of the fossils of the chalk generally, 

 but to describe those collected by Mr. Phillips. 



In the chalk with numerous flints, were found plagiostoma 

 spinosa, fragments of inoceramus, several species of terebratula, 

 several of echinus, and many cucumerine, clavated and muricated 

 spines. 



The fossils, which the author considers more particularly to 

 demand attention, are those flints of spongeous or alcyonic origin, 

 of which this stratum has afforded a numerous variety. In many 

 of these, no traces of organization are to be observed in the flint ; 

 but its origin is inferred from its peculiar form; in others the 

 flint is of a brownish colour, and displays the structure of the 

 spunge or of some other body allied to the Polype tribe. 



In the bed with interspersed flints, an imperfect nautilus was 

 found, and several species of terebratula, and of echini already 

 noticed, and the remains ofalcyonia and of sponges. A speci- 

 men of the plagiostoma spinosa was found with the valves 

 expanded and filled with flint. 



Some of the chalk exposed to the action of dilute muriatic 

 acid, developed a fine floculent substance, which fell on the 

 slightest agitation of the vessel. 



The chalk of the bed with few flints is heavier than that of the 

 preceding beds, and feels gritty, giving the idea of its being 

 blended with minute particles of sand ; it contains the palates of 

 fish in tolerably good preservation. The remains of alcyonia 

 and of sponges are also very abundant, and their structure is 

 more evident than in the preceding occasioned by a strong 

 impregnation of iron. Many shells of the genus terebratula, 

 agreeing with those found in the preceding beds, were collected 

 here, with two varieties of the plagiostoma spinosa, a valve of 

 inoceramus in extremely good preservation, a finely striated 



