1866.] SEELEY DEIFT OF THE FEiS^LAND. 473 



Under the shell-bed was a very fine sand, which was cut-down- 

 into 4 feet. It is grey-brown at the top, but darker lower down, 

 becoming argillaceous, and at a greater depth changing to a blue- 

 black clay clearly stratified, which is dug for biicks. Out of this 

 clay were got Septarian concretions, and fragments of a large-grained 

 Oolite and other rocks. The pits are very extensive about the March 

 railway -station ; and everywhere the gravel contains shells, though 

 they differ from pit to pit. 



Tracing this gravel south to Wimblingdon, near the railway-sta- 

 tion, the deposit, quite at the surface, and only a foot or two thick, 

 rests on one of those thin stonebands so common between the 

 Oxford and Kimmeridge Clays. It is a fine sandy gravel with the 

 usual shells ; but the argillaceous-limestone rock was drilled with 

 the burrows of Pholades, the shells still being in the holes. 



To the soutli the gravels are somewhat continuously spread along 

 by Chatteris, Somersham, Earith, St. Ives, Willingham, to Swaver- 

 sey. And in the spring of 1861, walking up the railway between 

 Over and Swaversey, I found the line had been made with gravel 

 dug on the spot, which was full of shells similar to those of March, 

 Tellina soliclida and Tiirritella communis being very common, and 

 Cardium edide not rare. The pits, which were just beyond Drayton 

 Gate-house are, unfortunately, filled in. North of March the gravel 

 is continuous nearly to Wisbeach. 



Marine Shells from March. 



E,hynclionella psittacea, 

 Corbula nucleus. 

 Astarte crebricostata. 

 Mactra elliptica. 

 Tellina proxiina. 

 Mya truncata. 



arenaria. 



Tellina solidula. 

 Ostrea edulis. 

 Cardium edule. 

 Purpura lapillus. 



Scalaria communis. 

 Trophon clathratus. 



scalaris. 



Buccinum undatum. 

 Bela turricula. 

 Turritella communis. 

 Litorina litorea. 



rudis. 



Natica helicoides. 

 Natica, sp. 



I will here notice a deposit at Hunstanton, as belonging to the 

 same geographical district. There are many pits between Hunstanton 

 and Brancaster where the gravel is thick and coarse ; but south of 

 the railway- station a hiU has been cut into for ballast, exhibiting 

 ash-coloured sands and gravels 30 feet thick without reaching the 

 bottom. The cross stratification is very marked, and the beds dift'er 

 much in difi'erent parts of the pit. In some of the bands pebbles 

 were almost as well rounded as on a pebble-shore like Dunwich. 

 Shells occur in several distinct bands of gravel, and at various 

 heights, but are most numerous and best preserved in the coarse 

 layers. 



This deposit is remarkable for the absence of local fragments 

 (the Eed Rock occurs but rarely, and then only in small pieces 

 which may have come from the north) ; for the included fragments 

 comprise every kind of rock, numerous granites, syenites, traps, 



2k2 



