and Fresihtsdaier Deposits of Eastern Norfolk. 363 



beneath the black earth was covered up in June hist, but ex- 

 posed to view in March, and examined by Mr. Simons. 



Fig. 10. 

 Runton Gap. 



drift. 



drift. 



chalk. 



chalk. 



a. Black earth with shells "I 



b. Reddish sand J 



c. Nor^vich crag in patches. 



fresliwater. 



I shall now describe, first the freshwater beds and their 

 fossils, and then the fossils of the subjacent layer of crag. 

 The black earth is heavy and turns greenish when dried. It 

 is sometimes divisible into layers, on the surface of whicii 

 shells are seen in a compressed state; but this is not always 

 the case, the shells being often uninjured and irregularly di- 

 spersed. Although the colour of this earth is doubtless due to 

 vegetable matter, I have not found seeds in it, but occasionally 

 small pieces of wood. The most shelly portions which I have 

 seen were sent to me before my last visit to Norfolk, through 

 the kindness of Robert Fitch, Esq., of Norwich. The red 

 sand below resembles the crag in colour and contains the 

 same shells, of which the following is a list, all of which 

 have been examined by Mr. G. Sowerby: 1. Paludhia vivi- 



Valvata piscinalis. 4. Limnca pa- 

 6. Planorbis imbricatus. 7. P. 

 ^ 9. Ancylus lacustris. 10. Cydas 



11. C appendiculata. 12. C. amnica^vo.r.'^ Besides 

 these is a small shell allied to Turbo ulva:, but apparently 

 different, of which I only procured one individual; also frag- 

 ments of Anodon. Among these twelve species the only one 

 which could not be identified with well-known British living- 

 species is the Cyclas, resembling C. aninica. It belongs to the 

 sub-genus Pisidium^ and is remarkable, says Mr. G. Sowerby, 

 " for its great proportional altitude, in which respect it differs 

 not only from the I'ecent P. amnicum, but also from the fossil 

 variety of P. amnicum, found at Grays in Essex. The concen- 

 tric ridges on the outside of each valve are much more pro- 

 minent than in the recent P. amnicum, particularly near the 

 beaks, and in this circumstance they resemble the Grays fossil 



2 B 2 



para, 

 lustris. 

 albus. 

 cornea 



2. P. impura. 3. 



5. Lj. stagnalis. 



8. P. mar^iinatus. 



