XL CORNBRASH. 155 



tints, with stony layers, and shells of marine and estuarine character, 

 with jet and other remains of plants, lie under the cornbrash, and 

 above the principal masses of calcareous rocks, which appeared to 

 Morris to be of the upper or Great oolite stage, both by continuity 

 of range and organic contents P. 



UPPER DIVISION OF THE GREAT OOLITE. 

 Cornbrash. 



In my early wanderings with the ' great disco verer" 1 of the oolites, 

 the thin rough shelly rock, which breaks up into ' brash ' and 

 makes good land for ' corn,' was always trusted as the upper limit 

 of the Bath oolite series ; and the continuity of a deposit rarely 

 exceeding eight feet in thickness, across England from Devonshire 

 to Yorkshire, was a theme of frequent contemplation. 



Only partially oolitic, rarely of much local utility except for 

 walling and road-making, it is yet very frequently exposed in 

 shallow excavations and over broad dry cultivated lands, and in 

 each case yields fossils in considerable abundance and variety, not 

 much different in general aspect from those of the Great oolite 

 below, and, like them, not usually yielding any belemnites or many 

 ammonites. 



On this account, as already observed, the fossils of the cornbrash 

 may be well included in a general catalogue of the fossils of the 

 upper and middle division of the Great oolite series. 



FOSSILS OF THE BATH OOLITE SERIES. 



The organic remains in the oolitic system, taken generally, 

 constitute one of the most complete records of the inhabitants of 

 land and sea which can be referred to in the whole series of ancient 

 life. Land plants, insects, reptiles, and mammalia ; lacustrine and 

 estuary shells, fishes, and reptiles ; marine corals, echinodermata, 

 annellida, Crustacea, bivalve, univalve, and cephalopodal shells, 

 fishes, and reptiles. 



A remarkable uniformity runs through the whole system : thus 



P Geological Proceedings, 1853. p. 31 7 V 



