and Freshwater Deposits of Eastern Norfolk. 353 



posit is unseen, but is probably not much below the level of 

 the sea, as Mr. Simons of Cromer tells me that he has seen 

 chalk 171 situ at Mundesley at low water. In 1829 I ob- 

 served a mass of the till prolonged in such a way into the 

 freshwater formation at the southern junction of the latter 

 with the drift as to imply the contemporaneous origin of the 

 lower part at least of both formations. (See diagram, fig. 2.) 



Fig. 2. 



gravel. 



freshwater. 



ti'J. 

 freshwater. 



Interstraiification of drift and freshwater at Mundesley. 



Yet 1 inclined then to the conclusion that the Mundesley 

 formation, which I traced for nearly 300 yards along the 

 coast, might, as a whole, be considered as the deposit of a 

 lake or hollow excavated in the drift. In 1839, when a new 

 section had been laid open by the sea, it appeared to me 

 rather that these strata of Mundesley were simply a large 

 development of those observable at the base of the cliff at 

 Hasborough and other places, and that their position rela- 

 tively to the drift might be represented by the diagram, fig. 3. 



Fig. 3. 



Mundesley. 



freshwater. 

 Position of the freshwater beds at Mundesky. 



We may imagine that while the coast was sinking gradually, 

 a small river may have entered here bringing down drift 

 wood, freshwater shells, mud, and sand, and the flow of the 

 stream may have partially counteracted those causes by the 

 influence of which the boulder formation was accumulating 

 in the spaces immediately contiguous. The following is a list 

 of the shells which I obtained from the Mundesley beds, in- 

 cluding some which Mr. Fitch of Norwich, and others which 

 Mr. J. B. Wigham have kindly communicated to me : 1. Pa- 

 ludina impura; 2. P. minuta^ Strickland, (see fig. 4) ; 3. Val- 

 vata cristata ; 4. V. piscinalis ', 5. Limiiea glutinosu; 6. L. 

 peregra; 7. Planorbis albua, var. (less flat, and aperture less 



