FOSSIL MOLLUSC A. 263 



Wotton, Sevenoaks, Nutfield, Pulborough, and Peters- 

 field. Near Folkestone there occur layers of a 

 siliceous limestone often full of Ostrea, Arca^ Lima^ 

 Exogyra, Pajwpcea, and Pecten. 



At Shotover Hill, near Oxford, there are strata 

 of this age which contain Unio^ Cyrena^ Palndina^ 

 and other fresh-water forms. In Bedfordshire (as, 

 for instance, at Patton, Woburn, Ampthill, Sandy, 

 Wicken, and Up ware) the sands are worked in order 

 to get at a " coprolite " bed, which is frequently as 

 much as two feet thick. These " coprolite " workings 



Fig. 242. — Inoceratnns sulcattis (.Gault). 



are capital places for fossils, all phosphatized, or 

 converted into phosphate of lime, and most of them 

 of considerable interest and importance, because they 

 have been " derived " or washed out of the older 

 formations where they were originally deposited, such 

 as the various strata of the Oolite and Wealden. 

 OstreUy Gervillea^ Exogyra, Gryphcea, etc., are very 

 common. 



The fossils of the Gault have always been admired 

 on account of their great beauty ; many of them still 



