58 GEOLOGY OF THE ISLE OF WIGHT 



It can be seen on the shore, when the tide happens to 

 have swept the sand away. Otherwise the lower beds are 

 hardly visible, there being no cliff here, but a slope over- 

 grown with vegetation. 



In Alum Bay the London clay, about 400 ft. in thick- 

 ness, consists of clays, chiefly dark blue, with sands, and 

 lines of septaria. In the lower part is a dark clay with 

 Pholadomya margaritacea, still preserving the pearly 

 nacre. There are also Panop&a intermedia, and in sep- 

 taria Pinna affinis. All these with their pearly lustre, 

 are beautiful fossils. A little higher is a zone with 

 Ditrupa, and further on a band of Cardita. Other shells 

 also are found in the clay, especially in the lower part. 

 They are all marine, and indicate a sub-tropical climate. 

 Lines of pebbles show that we are near a beach. In other 

 parts of the south of England remains from the land are 

 found, borne down an ancient river in the way we found 

 before in the Wealden deposits. 



But times have changed since the Wealden days, and 

 the life of the Tertiary times has a much more modern 

 appearance. From leaves and fruits borne down from 

 the forest we can learn clearly the nature of the early 

 Eocene land and climate. Leaves are found at Newhaven, 

 and numerous fossil fruits at Sheppey. The character of 

 the vegetation most resembled that now to be seen in India, 

 South Eastern Asia, and Australia. Palms grew luxuri- 

 antly, the most abundant fruit being that of one called 

 Nipadites, from its resemblance to the Nipa palm, which 

 grows on the banks of rivers in India and the Philippines. 

 The forests also included plants allied to cypresses, 

 banksia, maples, poplars, mimosa, custard apples, gourds, 

 and melons. The rivers abounded in turtle large 

 numbers of remains of which are found in the London 

 clay at the mouth of the Thames crocodiles and alli- 

 gators. With the exception of the south east of England, 

 all the British Isles formed part of a continental mass of 



