XVIII. — On the Crag-strata at Bramerton, near Norwich. 

 By RICHARD TAYLOR, Esq. of Norwich. 



[Read June 20th, 1823.] 



XT is well known that an extensive district, commencing near Harwich and 

 occupying- nearly all the eastern coast of Suffolk, contains a substratum, seve- 

 ral feet in thickness, of the crag-pit shells, which are used in many parts of 

 that district for agricultural purposes. Many of them approach in their spe- 

 cific characters to those shells which are discovered upon our shores ; while 

 they are associated with others whose species have ceased to exist. Together 

 with the shells are buried the remains of unknown animals. The Suffolk 

 crag, particularly that in the vicinity of Ipswich, has furnished an extraordi- 

 nary abundance of fossils to collectors, far exceeding in number those which 

 we are able to present from Bramerton. 



From Lowestoft to Bramerton, the crag shells are concealed beneath deposits 

 of alluvial gravel, sand, and clay, of considerable but irregular thickness. To 

 the east of Bramerton they have not, I believe, been recognised ; to the west 

 they may be observed at Whitlingham, immediately in contact with the chalk ; 

 they may also be traced forming thin beds above the chalk on the opposite 

 side of the Yare at Thorpe, and are not unfrequently met with, several feet 

 below the surface, on sinking wells in the city of Norwich. To the west of 

 Norwich I have not hitherto discovered them, but to the north they may occa- 

 sionally be observed at a few intermediate points between that city and Cromer. 

 The valley of Wroxham, Tke that of Norwich, is sufficiently deep to inter- 

 sect the crag, and to expose the chalk-strata, which here have attained a con- 

 siderable elevation, and rise through the alluvial beds to a level with the sur- 

 rounding country. At Cromer the crag passes into the sea immediately to 

 the west of the jetty, and huge agglomerated beds of it may be observed 

 scattered upon the beach at low-water mark. Prom these masses the best 

 specimens of shells may be collected. They consist chiefly of a small Mactra, 

 probably Mactra arcuata, and of Turbo littoreus, mixed with fragments of 

 Mya lata, of Cardia, and of Balani. The crag shells are continued along the 

 cliff about a quarter of a mile. Their position may readily be distinguished 

 by the continual tendency of the sand, in which they are imbedded, to slip 

 down, and to form heaps at the base of the cliff. The shells, in this as in 



