BRACKLESHAM BEDS. 



117 



middle or upper part of the Bracklesham Series, since pebbles 

 occur on various horizons at Bracklesham itself. 



_ Though the Bracklesham 'Beds of the Isle of Wight have only 

 yielded a small portion of the prolific fauna found at Selsey, yet a 

 considerable number of the most characteristic Bracklesham 

 species occur in both districts. Among the most conspicuous 

 may be mentioned Nummulites Icevigatus, Turritella imbricataria 

 (Fig. 23), and Gardita pli^nicosta (Fig. 22). 



Fig. 22. 



Cardita planicosta^ Lara. 



Fig. 23 



Turritella imbricataria^ Lara. 



Specimens of the Cardita obtained from the lower portion of 

 the beds at Whitecliff Bay are not only ranch less in size than 

 those found at Brackleshara, but are pierced by sraall boring 

 shells ; showing that the animals must have perished, and the 

 shells have remained a considerable time at the bottom of the sea 

 before they were covered by the sediment in which they are now 

 imbedded. 



The fauna of the Bracklesham Beds of the Isle of Wight 

 appears to show a sub-tropical climate, shoal- water, the proximity 

 of land, and perhaps estuarine conditions. The occurrence of a 

 coal-seam, resting on an ancient vegetable soil, indicates an eleva- 

 tion to a sufficient extent to raise the beds above the sea-level for 

 a portion of the time. 



Barton Clay. 



This group of strata which is displayed in the cliffs at Barton, on 

 the opposite coast of Hampshire, and is so well known to collectors 

 for the richness and abundance of its fossils, is here repre- 

 sented by clays overlying the Bracklesham Beds in Alum and 

 Whitecliff Bays. The nature of these deposits (which are com- 

 posed of sandy clays, clays, and sands with layers of septaria) is 



