322 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [JuilC 15, 



Pisidium pulchellum . 1 i.^ ,, 



.{, Mostly imma- 

 pusillum ft 



obtusale? J 



Helix hispida Rare. 



pulcliella Only two. 



aculeata (young) Only one. 



Carychium minimum Only two. 



Cypris (small species) One valve. 

 ? Candona lucens 



(young) One valve. 



Candona reptans Three valves. 



Spine of Echinus 



Belemnites 



Area 



Cerithium }■ 



Other casts aud frag- 

 ments of marine 



animals J 



Seeds and other vegetable remains, as 

 Ceratophyllum, Equisetum, &c. 



These are de- 

 rived from 

 the Oxford 

 Clay. 



The freshwater deposit on one side of the cutting appeared to be 

 intercalated with the superincumbent gravel, but on the eastern side 

 there appeared a well-defined line between it and the overlying gravel, 

 as if the freshwater deposit had been eroded ; the gravel forming a 

 continuous and uniform covering over this bed and the adjacent 

 sandy and argillaceous strata, in a depression of which the freshwater 

 bed had been previously accumulated. The gravel deposit consists 

 chiefly of rounded and angular flints, rolled quartz pebbles, and a few 

 other rocks, as oolite, &c., and some small sandstone boulders, irre- 

 gularly stratified with occasional layers of small pebbles, seams of 

 clay and loam, and others much mixed with a chalky paste, the 

 larger pebbles occurring at the base ; the gravel overlies 3 feet of 

 greyish brown sandy clay, containing fragments of Belemnites and 

 Gryphcea, with veins of gravel at the upper part, which is irregular 

 and wavy. 



Three miles to the westward, in the valley of the Gwash, another 

 freshwater deposit, about 6 feet thick, intercalated with gravel, has 

 been met with ; it contains land shells, &c., and bones, and may be 

 of slightly later date than the one above described. 



Barithorpe Cutting. — Valley gravel. — The gravel noticed in the 

 previous section again occurs at the northern end of the Banthorpe 

 cutting : and although at that spot of limited extent, and abutting 

 against the side of the hill, it forms a portion of a deposit which is of 

 considerable extent and thickness, sometimes attaining 20 feet, and 

 occupying chiefly the sides of the valleys and the upper surfaces of 

 the lower grounds through which the present drainage is effected. 

 This deposit consists of coarse rounded gravel of sandstone, oolite, 

 and flint, with occasional angular fragments, a few small boulders, 

 and interspersed patches and seams of sand ; the whole deposit being 

 coarsely stratified, and in some parts exhibiting vein-like markings 

 of chalky matter. This gravel occurs over a considerable area in this 

 district ; it may be observed at Ponton, near Little Bytham, and 

 around Uflington ; it must not, however, be confounded with the 

 smaller and more angular gravel of the present river valleys. 



The age of the Casewick deposit above described, which is con- 

 sidered to be posterior to the boulder-clay, may be related to those 

 found in the eastern district, as at Holderness, &c., and probably 

 also to that of Mundesley, described by Sir C. Lyell as occurring 



