LOWER GREENSAND. 367 



the name of ' Vectine ' (from Insula vectis of the Romans) was suggested by 

 Fitton in 1 845.1 



In Surrey, Kent, Sussex, and part of Hampshire the Lower 

 Greensand has been divided by Mr. F. Drew as follows: — 



4. Folkestone Beds. 

 3. Sandgate Beds. 

 2. Hythe Beds. 

 I. Athertield Clay. 



These divisions are well seen in the cliffs between Hythe and 

 Folkestone, where their united thickness is about 250 feet ; but 

 westwards they attain a thickness of 450 feet and more. In the 

 Isle of Wight and other parts of England, different divisions have 

 been made. (See p. 355.) From Reigate westwards the beds are 

 chiefly arenaceous, eastwards calcareous beds occur in places. 



The organic remains of the Lower Greensand comprise Plants, 

 Sponges, and Corals, Echinoderms, Annelides, and Cirripedes. 

 The INIollusca include Belemnites, Nautilus plicatus, Ammonites 

 Deshayesii, Ancyloceras ( Scaphites) gigas, Diceras Lonsdalei, Trigonia 

 caudata, T. alccformis, Gennllia anccps, Perna Mulleti, Ostrea frons, 

 Exogyra (Gryphcca) sinuata, Pauopcca Neocomiensis, P. plica ta, 

 Thetis Soiverbyi, Pecten orbicularis, Area Rauli?ii, Cvprina angulata ; 

 and the Brachiopoda include Terebratula sella, Rhrnclwnclla sulcata, 

 R. Gibbsiana, Terebratella oblonga, etc. Remains of Fishes are un- 

 common, they include Strophodus ; among Reptiles ?ir& Ichthyosaurus, 

 Iguanodon, Plesiosaurus, Poly ply chodon, and Protemys. 



In the South of England the Lower Greensand (and the 

 Punfield Beds where these beds have been identified) rests directly 

 on the Wealden Beds, from Kent westwards to Dorsetshire. 

 Traced northwards the Lower Greensand overlaps the Wealden 

 strata and rests on the Kimeridge Clay and Corallian rocks near 

 Devizes and Calne, and on the Kimeridge Clay near Swindon, 

 and on the Purbeck and Portland Beds in Buckinghamshire.^ (See 

 Fig. 58.) 



WEALDEN AREA. 



Atherfield Clay. 



This name was given by Dr. Fitton to certain strata which 

 overlie the Wealden Beds at Atherfield, on the south-western coast 

 of the Isle of Wight.^ (See sequel.) 



The formation consists essentially of clay, with, in places, con- 

 cretionary beds of shelly rock and calcareous bands. In thickness 

 it varies from 60 feet at Godalming to 20 or 30 feet between Hythe 

 and Sandgate. At Hythe it rests on shales with Cyprides, the 

 upper part of the Weald Clay (or Punfield Beds), while the junction 



1 Q.J. i. 189. 



2 Morris, G. Mag. 1867, p. 462. 



' Fitton, Proc. G. S. iv. 200 j Godwin-Austen, Ibid, 171. 



