Cornbrash. 1 8 1 



Pentacrinites, fragments of Echinodermata, Pectens, 

 Aviculce, Terebratulce, &c. In it occurs the Bradford 

 clay, in which is found the beautiful Crinoid, Apiocri- 

 nites rotundus, and also Terebratula digona, and many 

 fragments of Coniferous wood. 



On the south coast the Forest Marble borders the 

 sea for a considerable distance between Bridport Harbour 

 and Portland Isle, from whence it ranges north by 

 Wincanton to Frome in Somersetshire. A few miles 

 further north, the Great Oolite proper crops from under- 

 neath it near Norton St. Philip, and beyond this town 

 and Bath it everywhere overlies the Great Oolite, and 

 forms the surface of vast tracts of country between the 

 Avon, Cirencester, and Burford, in Gioucestershire, 

 beyond which, towards Witney, on the river Wlndrush, 

 it gets broken into outliers, and also becoming thinner, 

 it either dies out, or is gently overlapped by the Corn- 

 brash about three miles north of Bicester in Oxford- 

 shire. 



The COKNBRASH forms the uppermost member of 

 those formations that are usually classed as Lower 

 Oolite. It is generally of inconsiderable thickness (15 

 to 100 feet), and beginning in Dorsetshire between 

 Bridport and Weymouth, it ranges at the surface all 

 across that county, excepting where overlapped by the 

 Cretaceous strata between Abbotsbury and the neigh- 

 bourhood of Evershot. It is remarkably constant, 

 striking with the underlying and overlying strata all 

 through Wiltshire, Gloucestershire, Oxfordshire, and 

 Northamptonshire, and onward into Lincolnshire ; 

 but north of the Humber it disappears for a space, 

 being again overlapped by unconformable Cretaceous 

 strata. 



Throughout all this long range it retains in a 



