202 
THE CRETACEOUS ROCKS OF BRITAIN. 
Belemnite Marls. The occurrence of Act. plenus with Am. [ Ilapl .] 
Austeni at an horizon which is apparently nearer the base than the 
top of this zone is remarkable and, so far as at present known, is 
without parallel. The bed in which they occur is a very hard grey 
chalk, and as it is burnt for lime, along with all the other beds 
below the red band, it must be fairly calcareous. 
The red chalk is rather soft and marly, breaking into small angular 
blocks, the edges of which are pinkish white. All the joint-planes 
which cross this bed are also bordered by whitish bands about a 
third of an inch thick. These facts seem to show that the bed was 
originally of a uniform red colour, and that the water percolating 
from the surface has effected a certain amount of decoloration. 
Where it rises toward the surface, near the entrance of the pit, 
the upper part weathers yellow, and finally the whole breaks up 
into a rubble of yellowish chalk. 
North of West Bow the country slopes gradually toward the 
Fenland, and the surface is obscured by blown sand. 
No exposure of the Belemnite Marls has yet been found in Suffolk 
(north of the Lark). 
List of Fossils from the Lower Chalk of Cambridge and 
Suffolk. 
The following list of fossils is based on those given in the Survey Memoir 
on the Geology of the Neighbourhood of Cambridge (1881), and that on 
Parts of Cambridgeshire and Suffolk (Sheet 51, N.E., 1891). Most of the 
fossils herein recorded are in the Woodwardian Museum at Cambridge, 
but collections were also made from the localities mentioned by Mr. H. 
A. Allen for the Geological Survey in 1878. 
In this list the following letters are used to indicate the localities and 
districts mentioned 
a=Localities to the south and west of Cambridge. 1 
b=Cherry Hinton and Fulbourn. 
c=S waff ham, Beach, Burwell, and Isleham. 
s=Localities in Suffolk, principally in the fourth column, where it 
signifies the large quarry at West Bow. 
--» 
Cambridge 
Greensand. 
Chalk Marl. 
Totternhoe 
Stone. 
Chalk above 
Totternhoe 
Stone. 
1 
Belemnite 
Marls. 
Reptilia. 
Acanthopholia eucercds, Seeley - 
X 
,, stereocercus, Seeley - 
X 
— 
_ 
— 
— 
Anoplosaurus curtonotus, Seeley .... 
X 
— 
— 
— . 
„ major, Seeley ..... 
X 
, —* 
— 
S— 
— 
Cimolioaaurus Bernardi, Oiven ..... 
X 
— 
— 
•—i* 
,, planus, Owen ..... 
X 
— 
— 
— 
— 
Emys sp.. 
X 
— 
— . 
i ■' 
- ' 
Ichthyosaurus campylodon, Carter .... 
X 
— 
— 
b 
-■ — 
Lytoloma cantabrigiensis, Lyd. ..... 
X 
— 
— 
— 
- * 
„ sp. ........ 
X 
-- 
— 
— 
— 
Macrurosaurus semnus, SeeZey ..... 
X 
1 - 
— 
-- 
— 
Ornithocheirus Carteri, Seeley - 
„ Fittoni, Seeley . 
X 
— 
— 
— 
!_ 
— 
— 
— 
-t- 
—. 
,, sp.. 
X 
— 
b 
— 
Polyptychodon interruptus, Owen .... 
X 
— 
— 
b 
— 
Trachodon cantabrigiensis, Lyd. .... 
X 
_ 
- 
— 
— 
Saurospondylus dissimilis, Seeley .... 
— 
— 
b 
— s 
