174 GEOLOfiY OF THE ISLE OP WIGHT. 



Cerithium elegans. Melania turritissima. 



,, mutabile. Melanopsis carinata. 

 „ plicatum. „ fusiformis. 



Fusus Forbesii. Paludina lenta. 



Melania Forbesii. Balanus. 

 „ muricata. 



The occurrence of Melania turritissima so low in the Bembrldge 

 Marls breaks down the palgeontological line drawn by Forbes 

 between the Upper and Lower Marls. Like many other Oligocene 

 fossils, this species is commonly confined to certain thin beds, 

 but reappears on widely separated horizons. Even in the Hea- 

 don Series, a scarcely distinguishable variety is met with under 

 the name of Melania. -per acuminata. The specimens of Cerithium 

 plicatum are not perfect, but there seems little doubt that they 

 are correctly determined, and that the occurrence of this species 

 so far from its principal horizon is another case of the same kind. 



North of the Priory the beds rise, and the Marls are lost in 

 the overgrown part of the cliff, or pass inland. The only section 

 near Sea View is in an old pit on the road to Fairy Hill, where a 

 bed with Oysters overlies the Limestone, but no measurements 

 can be obtained. 



The inland sections near Bembridge and St. Helen's are few 

 and unimportant, the most interesting being a small exposure of 

 the Oyster bed on the Limestone at the edge of Brading Harbour 

 north of Woolverton ; and a brick pit, showing mottled clay with 

 bones of turtle, on the northern border of the harbour, near 

 Carpenters. 



A well-section, communicated by Mr. Parsons, shows that 

 close to St. Helen's Station the Bembridge Limestone has sunk 

 considerably beneath the sea-level, rock being reached at 28 feet 

 from the surface, which is about 5 feet above high water. In the 

 p, oil heap were found the ordinary fossils belonging to the base of 

 the Bembridge Marl, including Ostrea vectensis. {See Appen- 

 dix, p. 309.) 



Another well on the top of the hill about a quarter of a mile 

 north of St. Helen's reached the limestone at 133^ feet. Perhaps 

 15 feet of this depth belong to the Hamstead. Beds, leaving 

 118^ feet as the total thickness of the Bembridge Marls. Scarcely 

 any determinable fossils were found in the samples, but Scrpula 

 occurs about 7 feet above the Limestone. 



Hamstead Beds or Gravels hide much of the Bembridge Marls 

 west of Brading Harbour. As there are also few pits and no 

 clear cliff-sections, little can be said about the changes this series 

 undergoes between Sea View and the Medina. At the time of 

 writing there are no good sections near Ryde. 



The u])per part of the Bembridge Marls can be examined in 

 Ashlake Brick Yard, near Wootton Bridge. Here the following 

 section was observed : — 



Ashlake Brick-yard. 



Ft. In. 



Drift or Rainwash. Stony clay - - - - 3 6 



{Weathered clay - - - -40 



Black clay full of lignite (the Black 

 Band) - - - - 5 



