82 



FORAMINIFERA OF THE CRAG. 



of the deposit he estimated at 83 feet. In 1872 Messrs. S. V. Wood, jun., and 

 F. W. Harmer 1 questioned "the constancy or determmability of such horizons;" 

 and, by another method of calculation, arrived at the conclusion that the total 

 thickness of the Coralline Crag does not exceed 60 feet. That there are two 

 main divisions of the Coralline Crag is recognised by the several writers, and 

 appended is a comparison of their views. 



General Section of the Coralline Crag. 



After Professor Prestwich. 



Zone. Thickness. 



© 



to 



ft 



I'otal 



6' 0" 



30' 0"-( 



5' 0"| 



12' 0" J 

 15' 0"| 



10' 0"] 

 4' 0"{ 



r o"{ 



83' 0" 



Character of beds. 



Sand and comminuted shells 



A series of beds consisting 

 almost entirely of comminuted 

 shells and remains of Bryozoa, 

 forming a soft building stone. 

 False stratification and oblique 

 bedding are its constant cha- 

 racters 



Sand with numerous entire shells 

 and seams of comminuted 

 shells 



Sands with numerous Bryozoa, 

 often in the original position 

 of growth, and some small 

 shells and Echini 



Comminuted shells, large entire 

 or double shells, and bands of 

 limestone in the upper part 



Marly beds with numerous well- 

 preserved and double shells, 

 often in the position in which 

 they lived 



Comminuted shells, Cetacean 

 remains, Bryozoa 



Phosphatic nodules and Mam- 

 malian remains 



Localities. 



Sudbourne, 

 Gedgrave 



Sutton, 



Sudbourne, 



Gedgrave, 



Iken, 



Aldborough 



Sutton, 



Iken, 



Sudbourne, 



Gomer 



Sutton, 

 Broom Hill 



Sutton, 



Broom Hill, 



Sudbourne, 



Iken, 

 Tattingstone 



Sutton, 

 Ramsholt 



Sutton 



Sutton 



After Messrs. S. V. Wood, jun.. 

 and F. W. Haemer. 



3'". Bed reconstructed out of 

 3" comminuted. 



3". Solid bed of Molluscan re- 

 mains, with various species of 

 Bryozoa. " The Bryozoa rock- 

 bed of the Coralline Crag." 



3'. Calcareous sands, in some 

 places more or less marly, 

 rich in Molluscan remains 

 " The shelly sands of the 

 Coralline Crag." 



Total thickness GO feet. 



1 ' Supplement to the Crag Mollusca,' Palseontograph. Soc, 1872, p. ii, et seq. 



