144 THE CRETACEOUS ROCKS OF BRITAIN. 
Summary. 
From the above descriptions it will be seen that between Sid- 
mouth and Branscombe Mouth the Cenomanian is naturally divisible 
into three beds, and Mr. Meyer, who worked from Sidmouth east¬ 
ward, was perfectly correct in distinguishing three separate beds. 
One would certainly have supposed that they would be equally 
distinguishable at Hooken Cliff and Beer Head, where the group 
attains its maximum development, but this is not the case, for at 
these points there are only two beds. To account for this, three 
suppositions may be made : (1) The middle bed may have thinned 
out and disappeared, (2) it may have become amalgamated with 
the upper bed, or (3) with the lowest bed. 
In 1874 Mr. Meyer thought he found it in the lower part of the 
upper bed, but I cannot agree with that view; the differences, 
both faunal and lithological, seem to me considerable, and I regard 
the whole of the upper bed (B) at Hooken simply as an expansion 
of Mr. Meyer’s No. 12. The abundance of Holaster subglobosus 
seems to me nearly sufficient to settle the point. 
On the other hand, nearly all the fossils which occur in No. 11 
(A2) of the more western sections have been found in the upper 
part of the lower bed at Hooken and Beer Nead. Ammonites 
Mantelli, Pecten asper, the large Limas, several Trigonice, and the 
peculiar Holaster altus are common in both. Both are fine-grained 
shelly limestones, and we have seen that in the fallen blocks below 
Maynard’s Cliff there is a complete downward passage from No. 11 
(A2) into No. 10 (Al). Hence it seems to me highly probable that 
there is a similar amalgamation at Hooken, and that the 18 feet 
of rock at Hooken which Mr. Meyer referred to his Bed 10 is really 
equivalent to both 10 and 11. 
In passing round Beer Head this combination of 10 and 11, 
which I have called Bed A, can be seen in the process of thinning 
till it is condensed into a bed not more than 3 feet thick. This 
thinning is partly condensation and partly a thinning out of its 
lower portion, i.e., of the representative of 10, and nowhere along 
the Beer Cliffs did I see any of the coral-like Ceriocava ramulosa, so 
that it is either absent or rare. Here, as elsewhere, it is, in my 
opinion, Bed 11 or the upper part of A which is most persistent, 
and which has yielded by far the larger number of fossils that have 
been collected from the Cenomanian of the Devon cliffs. 
At Beer and Whitecliff the total thickness is in places reduced 
to less than 2 feet, and the upper bed (B) is always thinner than 
the lower bed (A). The composition of the beds in the more eastern 
cliffs has already been sufficiently explained. 
