VINE : POLYZOA A.^D MICROZOA OF YORKSHIRE AND NORFOLK. 369 
Cretaceous Series in West Suffolk, the authors, Messrs. A. J. Jukes- 
Browne and W. Hill, remark as follows : — 
We are now in a position to indicate the bearing of our work 
on the debated question of the exact age of the Red Chalk. In the 
absence of anything like ordinary Gault, Upper Greensand, or Chalk 
Marl at Hunstanton, the remarkable stratum wliicli there lies at the 
base of the Chalk has been referred by different observers to each of 
the formations which appeared to be missing, to the Gault by most of 
the early writers and by Mr. Wiltshire, to the Upper Greensand by 
Prof Seeley fon the streugth of its fossils being similar to those of 
the Cambridge Greensand), and lastly to the Chalk Marl by Mr. 
Whitaker. Every one, however, has discussed the question prin- 
cipally from a local point of view, founding their arguments mainly 
upon a consideration of the rock and its fossils as seen at 
Hunstanton," 
After stating their views rather more fully the authors seem 
to find a decisive answer to the question of age in the following 
premises : — 
1. " That the Norfolk Gault becomes increasingly calcareous towards 
the north, till at Dersingham it passes into 7 feet of marly and 
chalky material, the lower part of which is coloured red. 
2. That the microscopical structure of the Hunstanton Rock bears 
the same relation to the red and yellow marls of Dersingham 
that the hard chalk marl of Norfolk does to the softer Chalk 
marl of Cambridge. 
3. That the hard whitish limestone which overlies the representative 
of the Gaults from Grimstone to Dersingham is identical, in 
our opinion, with the so-called " sponge-bed" which overlies 
the Red Rock at Hunstanton. 
4. That the fossils are chiefly Gault species, and are such as would 
constitute a deep-sea fauna contemporaneous with that of the 
shallower and muddier water in which the Gault of South 
England was formed. 
From these premises we come to the uncontrovertible conclusion 
that the Red Rock of Hunstanton must be the equivalent of the 
Gault, and not of its upper divisions only but that it is a condensed 
