166 NEOZOIC TIME. [CHAP. X. 



and in Norfolk there are clays and soft sands which may 

 be of the same age ; but how far they may originally have 

 extended southwards we do not know. 



The Vectian 1 group is most completely and clearly ex- 

 posed in the Isle of Wight, where it is divisible into three 

 portions : (1) Atherfield Beds, 150 feet, chiefly clays ; (2) 

 Walpen Sands, 400 feet ; (3) Shanklin Sands, 256 feet. 

 They are entirely marine, and the deposits of a shallow sea, 

 rather deep and muddy at first, but becoming shallower 

 afterwards. The basement bed of the Atherfield Clay is a 

 seam of coarse grit containing small pebbles, with the teeth 

 and bones of fishes ; of this Mr. Meyer remarks, " it is just 

 such an accumulation of sediment as would result from the 

 dispersion of shore deposits over the floor of a moderately 

 deep lake. The fish-bones are those possibly of inhabitants 

 of the Wealden waters, and their presence at the junction 

 of the two formations may be due to the suddenness of 

 their destruction by the change from fresh to salt water." : 



The Atherfield Clay is the deposit of a deepish gulf or 

 estuary, but the Walpen Sands are current -formed beds in 

 shallower water, and this fluviatile action is very evident 



1 Vectian. This group is usually known as the Lower Greensand, 

 although it has long been admitted that this is an awkward and incon- 

 venient appellation. So long ago as 1827 Fitton protested against its 

 use ; in 1845 he suggested the name Vectine in its stead, and in 1885 I 

 proposed that of Vectian, which is only Fitton's term in another form. 

 The fact that Phillips applied this name to the Upper Eocene Tertiaries 

 cannot be held as any objection, for Fitton has undoubtedly a prior 

 claim to it, and since the Fluviomarine series is now known as the 

 Oligocene, no one is likely to revive Phillips' use of Vectian. The term 

 Upper Greensand is equally indefensible, for the beds so designated are 

 not a separate group, and should be united with the Gault under a new 

 name. In the following pages I shall use the name Vectian for all 

 strata that are equivalent to the beds between the Wealden and the 

 Gault, such as the upper part of the Speeton Clay, which no one likes 

 to call Lower Greensand, and which it is incorrect to call Neocomian. 



2 " Quart. Journ. Geol. Soc.," vol. xxviii. p. 248. 



