378 Mr. R. Taylor on the Alluvial Strata 5fc. of Norfolk and Suffolk. 



In the precincts of Norwich there is considerable variation at the different 

 pits in the fossil products of the chalk. Thus in the pits at St. Giles's gates, 

 ostreae are most abundant ; echini and the Terebratula plicata are most nu- 

 merous and best preserved in the Pocksthorpe pits ; large fragments of 

 inocerami prevail most in those of Thorpe ; pectines and trochi in those of 

 Magdalen Chapel ; while the belemnites and smooth terebratulae are pretty 

 equally diffused throughout them all. 



At Letheringset and Holt, towards the northern coast of Norfolk, we find 

 the chalk nearly similar in its substance and organic remains to the chalk at 

 Norwich. At Thornham, further westward, it contains enormous paramou- 

 drsc, alcyonites, fragments of large inocerami, conuli and cidares. 



The chalk in the excavations around Swaffham belongs probably to some 

 intermediate bed between the upper and lower strata. It presents one pecu- 

 liarity in the disposition of the layers of flint, two layers, forming a pair, 

 being set at the distance of a foot apart, and each pair at the distance of 

 several feet from the next pair. The chalk at Swaffham contains radiated 

 pyrites and the following organic remains, viz. two species of Terebratula ; 

 Inoceramus Cuvieri from one to twelve inches long ; plagiostomae ; two spe- 

 cies of Patella; serpulae resembling planorbes ; spatangi ; cidares and species 

 of echinites ; alcyonites ; madreporites, teeth of fishes, and fossil wood. 

 No belemnites are found in the chalk in this neighbourhood. 



Seven miles to the westward of Swaffiiam, at Marham, we arrive at the 

 western escarpment of the chalk, the lower beds of which are here exten- 

 sively worked. These are less white and more dense than the superior beds, 

 and are sufficiently hard for building, the church, the adjoining abbey, and a 

 tomb within the church with recumbent figures, having been principally con- 

 structed of this material. The fossils of the lower chalk are a Spatangus ; 

 Discoides subuculus ; Inoceramus Cuvieri ; Chama ? three or four species of 

 Terebratula ; a Gryphaea ; a small Ostrea ; a small Pecten ; Ammonites Green- 

 ovii ; flustrae attached to echini and inocerami ; claws of the lobster ; the teeth, 

 jaws, and palates of fishes, and fossil wood. Belemnites are very rarely found. 



The lower beds of hard chalk are completely exposed in Hunstanton cliff 

 for the distance of a mile, the lowest stratum consisting of red chalk, which 

 re-appears on the opposite coast of Lincolnshire. Tiiis red stratum is cha- 

 racterized by an abundance of very small belemnites. They seldom exceed one- 

 eighth of an inch in thickness, and are from half an inch to an inch in length. 

 They are largest in the middle ; sharply pointed, smooth and polished on the 

 surface, unusually translucent, of an aniber colour, and sometimes pearly. 

 The fossils of the hard chalk at Huns'.anton nearly agree in other respects 

 with those of the hard chalk at Marham. 



