20 Kemmrd ^ Warren — Tufa Deposit in Tutland Bay. 



(that is, as seen in the cliff section), in a north-easterly direction, 

 or away from Heaclon Hill, Mr. Trimmer gives the section as- 

 follows : — 



ft. ins. 



e. Warp -drift of brown loam 5 



c. Cream-coloured marl, with calcareous concretions, and a few thin 



black seams coloured by vegetable matter ; land-shells 2 6 



b. Sand lilackeued by organic matter ; calcareous concretions and 



land-shells 4 inches to 1 



a. Calcareous tufa ; laud-shells 10 inches to 2 



In describing the calcareous concretions, Mr. Trimmer states that 

 some are cylindrical and others sub-globular. The former have 

 often a cavity through the middle, w^hich is occasionally filled with 

 decayed vegetable matter ; thus showing them to have accumulated 

 round the twigs and stems of plants, as their form suggests. He 

 also considers that many of the sub-globular concretions may have had 

 land-shells for their nuclei. This author records : Helix [ = Helicigona] 

 arbustorum or nemoralis ; Helix [ = Hygromia] hispida ; Cyclostoma 

 elegans [== Pomatias reflexus~\. 



Professor Edward Forbes confirms Mr. Trimmer's account, and 

 gives the following section, though without stating its exact position 

 in the cliff section : — 



it. ins.. 



e. Loam, with scattered Helices, fragments of fliuts 6 



Helix [ = Helicigona] arbustorum or nemoralis, Cyclostoma elegans 

 [= Pomatias reflexus'], abundant. 



d. Clay-bed more full of shells. 



Limncea palusfris, Helix [ = VnlloHia] pulchella, Helix 

 cricetorum [ = Helicella itala'], Helix [ = Hygromia'] hispida, 

 Zua [= CochUcopa'\lubrica,Ach(itina\_= CaecilianeUa^acicicla. 



c. Bluish carbonaceous marl, shells most plentiful 2 0" 



Succinea oblonga, Cyclas. 

 a-b. White tufaceous marl, saudy in places, becoming purplish towards 



base, and somewhat stratified 3 8 



Cyclostoma elegans [ = Pomatias reflexus'], Clamilia, Succinea 

 oblonga, Cyclas or Pisidium, Helix hortensis, Helix [ = Pyra- 

 viidula] rotundata, Helix [ = Vitrea] cellaria. 



Mr. H. W. Bristow describes the deposit generally as con- 

 sisting of : — 



e. Brown loam, of unequal thickness, with scattered angular flints. 



d. Brown clay with perished shells. 



a~c. Calcareous tufa, 4 to o feet thick, sometimes equalling the Limnnean limestone 

 in hardness, finer at the top and coarser below, and with a few black 

 lines caused by decayed vegetable matter. 



Since these last-named authors examined the deposit for the 

 memoir of 1856 on "The Tertiary Fluvio-Marine Formation of the 

 Isle of Wight." no further information concerning it appears to 

 have been obtained. 



It was largely owing to a remark in a former paper ' that one 

 of us was led to collect from this deposit. Thougli the cliff was 



1 A. Santer Kennard aud B. B. Woodward, "The Post-Pliocene Non-Marine 

 Mollusca of the South of England " : Proc. Geol. Assoc, 1901, vol. xvii, p. 231. 



