224 Upper Greensand. 



stone, and other lithological varieties, can be traced 

 all along by Westerham, Merstham, GKiildford, the 

 Hog's Back, Farnham, and the extreme west of the 

 area in the country round Binstead, Selbourne, and the 

 ground about two miles west and south of Petersfield, 

 where, as far as colour goes, it might often be taken for 

 chalk. 



On the south side of the Wealden area, the Upper 

 Greensand maintains the same general character by 

 Cocking and Barlavington as far as Steyning, where its 

 lithological character begins to change, and the beds 

 pass into ' sandy marl and marly sand,' and near East- 

 bourne the strata are decidedly sandy. 



Important deductions are to be drawn from the 

 consideration of the lithological changes that take place 

 in the character of the Upper Greensand, which will 

 afterwards appear. A gradual change may be traced 

 all the way from Devonshire to Cambridgeshire and the 

 east end of the Wealden area, which throws some light 

 on the physical geography of the time, especially when 

 taken in connection with the circumstance, that out of 

 more than 200 species of fossils in the Gault, about 46 

 percent, pass onward into the Upper Grreensand. 1 The 

 Upper Greensand is often fossiliferous, containing 

 Cycads and Coniferous woods; Sponges, Siphonia 

 pyriformis, &c. ; a few Foraminifera ; Corals, Trochos- 

 milia tuberosa, Micrabacia coronula; many Echin- 

 oidea, the chief of which belong to the genera 

 Cidaris, Cardiaster, Echinus, Pseudo-diadema, 

 Salenia* &c. Brachiopoda are common, Terebra- 

 tulce and Rhynchonellce (T. biplicata, RTi. latissima, 



1 For much information on the Upper Greensand of the 

 Wealden area see ' Memoirs of the Geological Survey, Geology of 

 the Weald,' by W. Topley, 1875. 



