136 
THE CRETACEOUS ROCKS OF BRITAIN. 
Thus we find that Beds A and B, which are only about 7 feet 
thick above the centre of Little Beach, have thickened to no less 
than 23J feet at Hooken Cliff, with the further addition of 6 feet 
of glauconitic sand, making a total of nearly 30 feet for the 
Cenomanian part of this cliff. 
With respect to Bed A, the base was not seen on the shore or at 
the Pinnacles, but in Hooken Cliff it is visible where not obscured 
by down wash, and,, as usual, it rests on a well-marked even surface 
of the uppermost Selbornian sandstone. There can be no doubt 
that it is the same as the 11 feet of fossiliferous grit of Beer Head¬ 
land, nor that it is the “ bed 10 ” of Mr. Meyer’s paper on the Beer 
Head sections; but it seems to me equally clear that it is only an 
expansion of the bed which he numbered 11 at Whitecliff, and 
that the bed which he took to be 10 at Whitecliff is the uppermost 
calcareous sandstone of the Selbornian stage. 
Bed B has changed its character to some extent in thickening 
out; there is now only one layer of green-coated nodules, and this 
is at the top; the loAver part is quite free from such nodules, and 
forms a somewhat massive, whitish limestone full of quartz grains 
with patches and nests of greener, more glauconitic sand. Mr. 
Meyer has kindly shown me the original section he took at Hooken, 
and it is the lower half of this bed which he has numbered 11. It 
is characterised by the abundance of Holaster subglobosus of typical 
form, although this fossil does occur in upper part of the bed, and 
also in the upper 3 feet of the bed below (A). Mr. Meyer’s Bed 12 
at Hooken is the upper part of what I have here called B. 
Bed C is Mr. Meyer’s Bed 13, and his description of it, as seen 
at Hooken Cliff (Beer Head in his paper), is sufficiently accurate, 
but I think he was mistaken in identifying it as a definite bed else¬ 
where. It does not seem to me to exist as a bed even in the slipped 
masses on the shore below the Pinnacles, but the glauconitic mate¬ 
rial of it and some of its fossils have been worked up into the base 
of the Turonian limestone. Its most characteristic fossils are 
Actinocamax plenus and varieties of a Rhynchonella, which appears 
to be the Rh. Wiesti of Quenst. A form like Rh. mantelliana is 
also present. There are also a number of derived phosphatic 
fossils, among which is Am. [Acanthoceras] hippocastanum, though 
this does not occur in the beds below. 
In the upper part of C I found Galerites subrotundus (a Turo¬ 
nian species), and there is a complete passage from this bed into 
the hard nodular Turonian chalk, so that physically it is rather 
the base of that stage than the top of the Cenomanian. 
The group of beds just described can be followed with the eye 
for several hundred yards to the westward, but the rise of the beds 
in that direction takes them high up into the cliff, and it is impos¬ 
sible to say how far B and C extend. It is certain, however, that 
they either thin out or were cut out by contemporaneous erosion, 
and that much of the overlying chalk also disappears, until finally 
the soft chalk of the Terebratulina zone comes to rest on an 
eroded surface of the basal part of Bed A. 
