416 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Mar. 21, 



"Westward, at Sittingbourne and Upnor, it is thinner, and beyond 

 the latter place is not seen, unless it is represented by the sand 

 which, as aforesaid, sometimes occurs above the pebble-beds in West 

 Kent. 



A strange form of selenite seems to be characteristic of the Old- 

 haven sand both at Upnor and the Eeculvers ; it consists of crystals 

 with grains of sand caught up between the thin plates, which gene- 

 rally cause a peculiar satin-like lustre, but sometimes are in such 

 plenty as to make the mineral look like concretionary sandstone. 

 These crystals are of various sizes ; they often lie with their longer 

 axis vertical or oblique to the bedding, most likely from having been 

 formed in cracks ; and now and then casts of shells are made up of 

 them. 



Note on the Fossils from the Olclhaven Beds at Grove Ferry. 



I think it right to correct a mistake, of some importance, that has 

 been made with regard to a section in the Oldhaven Beds, and the 

 more so as it is printed in the Society's Journal. 



In 1859 a short paper, " On Some Tertiary Fossils found at Grove 

 Perry " *, was published by the late Mr. J. Brown, F.G.S., who stated 

 therein that " the beds forming the central portion of this hill above 

 Grove Perry would appear, according to Mr. Prestwich's sections 

 to belong to the ^ Basement-bed of the London Clay ' (Old- 

 haven Beds) but many of the fossils which I collected here 



appear to have an Upper Tertiary character; indeed some 



cannot be distinguished from Crag species." 



Now there can be no doubt whatever as to the age of the sand 

 in question. It belongs, as Mr. Prestwich has always held, to the 

 series called " Oldhaven Beds " in this paper. Its lithological cha- 

 racter is quite enough to settle the matter : no field- geologist who 

 had worked at the many sections in the neighbourhood could doubt 

 for a moment which of the Tertiary sands the pit is in, much less 

 could one who had mapped the district and traced the continuous 

 outcrop of each. 



As for the fossils, I could never find any but the common shells, 

 &c., of the Oldhaven Beds ; nor could Mr. Dowker, who has been 

 there often. The section, however, is smaU, and parts once open 

 may now be hidden. 



Mr. Prestwich having told me that he thought Mr. Brown had by 

 mistake mixed up some Crag fossils with those from Grove Perry, 

 and that the reported occurrence of Crag species at that place was 

 therefore open to great doubt, I carefuUy looked through the collec- 

 tion, now in the British Museum. The result of this examination 

 was to convince me that most of the fossils were really from the 

 Oldhaven sand, and that therefore any mistake in the list must have 

 been chiefly owing to the wrong determination of the species. The 

 following remarks show the main points wherein I differ from 

 Mr. Sowerby's identifications. 



* Quart. Journ. Geol. Soc. vol. xv. p. 133. 



