Norwich Geological Society. 233 



truly arctic shells occurring in great profusion, no instance existing 

 elsewhere in the Crag series of such a profusion oi Astarte horealis as 

 occurs at the base of the Belaugh deposit, which is literally paved 

 with these shells. 



Stratigraphically also these beds differ from those at Horstead, 

 Coltishall, and Burgh. The strata resting on the Chalk at those 

 places are as follows, in descending order : — 



(D.) Eed sand with pebbles. (C.) Laminated micaceous sands 

 and clays (the Chillesford Clay). (B.) Fine whitish quartzose sands. 

 (A.) Chalk. 



The shells at Horstead, Coltishall, and Burgh are found in the 

 bed (B) within a few feet of the Chalk, overlaid by the Chillesford 

 Clay(C). 



At Belaugh, on the contrary, the bed which contains the Tellina 

 solidula is not in these white sands, but in the red pebble beds (D), 

 which at Horstead, Coltishall, and Burgh overlie the Chillesford 

 Clay ; and the shell-bed is from 10 to 15 feet distant from the surface 

 of the Chalk, as determined by Mr. Gunn and the author, by sinking 

 a hole down to the latter. These pebbly sands, which are a wide- 

 spread deposit, appear, at this place, to have eroded the Chillesford 

 Clay, and completely destroyed it. Mr. Wood and the author con- 

 sider the thin irregular band of clay, at the base of the shell -bed 

 at Belaugh, has been derived from the destruction of the Chillesford 

 Clay hard by, during the formation of the slight trough in which the 

 Belaugh sands repose ; but although they think that this clay band does 

 not represent any portion of the Chillesford Clay in situ, they feel no 

 doubt that the shells at this jolace ai'e in the bed (D), and not in the 

 bed (B). At Weybourne the pebbly sands which contain the shells, 

 and the base of which is called Crag, rest directly on the Chalk. 



When sinking to the Chalk at Belaugh, a shell-bed (considerably 

 lower than those exposed in the section in which the Tellina solidula 

 occurs) was met with. This bed rested upon the thin clay-band 

 before mentioned, and in it but very few specimens of Tellina 

 solidida and Littorina littorea (so profuse in the upper part) could be 

 detected, but it was almost exclusively composed of Asfarte horealis 

 in a continuous layer, with occasional valves of Astarte compressa 

 and Gyprina Islandica, the shells forming a complete pavement to 

 the fossiliferous pebbly gravels, and with the thin clay-band 

 separating them from the bed (B). 



The position of the Belaugh deposit relatively to the Chillesford 

 Clay seen in section at Horstead and Coltishall, a mile on the west, 

 and again at Hoveton, near Wroxham Bridge, a mile on the east side of 

 it, appears to be that it occupies a shallow trough excavated between 

 the two places. 



The excavation of this trough appears to have entirely removed 

 the Chillesford Clay at Belaugh, so as to leave the shelly deposit of 

 that place resting upon the white sands which contain the Chilles- 

 ford shell-bed (a bed which is extremely inconstant so far as the 

 presence of fossils is concerned, although the sand itself is always 

 constant), and the thin band of clay down to which Mr. Fisher dug, 



