Proc. Yorksh. Geol. & Polyt. Soc, Vol. XII., PI. XXII. 
Upper Chalk. 
(Scale of 200 ft. to an inch.) 
Middle and Lower Chalk. 
(Scale of 100 ft. to an inch.) 
Chalk Rock 
Zone of 
Bel. mucronata 
Zone of 
Marsupites 
Zone of 
Micraster 
coranguinuin 
Zone of 
Ter. gracilis 
Zone of 
Rhyn Cuv'eri 
Melbourn Bock 
Belemnite Marl 
Zone of 
Hoi. eubglobosus 
Zone of 
Am in. varians 
Chloritic Marl 
Upper 
Greenaand 
Zones after Barrois, thickness of 
Lower Chalk corrected by Geol. 
Survey Memoir. 2nd Edition. 
Zone of 
M. cortestudinarium 
and M. breviporus 
A Diagram of the Zones of the Chalk as developed in the Isle of Wight. 
