PKESTWICH CEAG-BEDS OP SUPFOIK AND NOKFOLK. 



459 



At Coltishall, 8 miles N. of Korwich, the relation of the Crag to 

 the Chillesford Clay is again clearly shown in the pit at the lime-kiln 

 (fig. 29). 



Pig. 29. — Chalk-pit, CoUishall 



feet. 



8. Boulder-clay (traces of). 



5. Oclireous and ferrugi- 

 nous sand and shin- 

 gle 12 to 15 



3. Grey clay, with a few 

 fragments of wood 

 and a seam of peb- 

 bles (Chillesford 

 Clay) 6 to 8 



2'. White sand and fine 

 gravel, with patches 

 of shells and large 

 flints at base (Nor- 

 wich Crag) 4 to 6 



The shells collected by Mr. Eeeve* and by myself in bed 2' are: — 



--=- Chalk. 



Astarte borealis. 



compressa. 



Cardium edule. 

 Corbula nucleus. 

 Cyprina islandica. 



Mactra ? 



Mya arenaria. 

 My til us edulis. 

 Pecten opercularis. 

 Tellina obliqua. 

 prsetenuis. 



Littorina littorea. 



rudis. 



Purpura lapillus. 

 Scalaria groenlandica. 

 Turritella incrassata. 

 Natica catena. 



Helix hispida. 

 Limntea palustris. 

 Planorbis complanatus. 



Teeth and bones of the Mastodon are occasionally found at the 

 base of the same bed. One of the workmen informed me that he 

 had also found bones above the clay (3). 



In the closely adjacent pits at Horstead the Chillesford Clay may 

 be seen holding the same position. But in one pit (the old water- 

 channel) the sand bed (2') under the clay is not fossiliferous, 

 whereas the one above it (5) is ; whilst at the farmyard- pit, close 

 by, the lower bed (2') is fossiliferous and 5 is not. An entire skele- 

 ton of Mastodon is said to have been discovered in 2' some years since. 



Thence we pass to the coast at Cromer without meeting any 

 more Crag-pits f. At Cromer traces of the Crag were found lying 

 on the chalk in digging the foundations of the jetty ; but no section 

 of it is seen until we reach Eunton Cliff. At a short distance 

 west of the Gap a ferruginous pebbly mass of crag, 2 feet thick, 



* In addition to these, Mr. Reeve has found in the same bed at Wroxham, 

 two and a half miles S.S.E. of Coltishall pit, Nucula Cobholdim, N. tenuis, Leda 

 limatula, Lucina borealis, Mactra subtruncata, M. solida, Tellina lata, Anomia 

 epMppium, Trophon antiquum, and Pecten tigrinus, but no freshwater shells, no 

 Turritella, and no Astarte borealis. 



t My friend the Bev. J. G-unn has this summer been with me to the pits 

 at Burgh, between Coltishall andWeybourne. The Chillesford Clay is again well 

 exposed there, and overlies a foot or two of pebbly sand, which contains in places 

 a few Norwich-Crag shells. 



