300 ON THE ZONAL STRATIFICATION OF THE
stones, the size of the foramen speaking of the strong attachment
needed in such a shifting sea, and oblique cross bedded sands.
Only a few mammal bones and teeth were found at Waldringfield,
the region between Newbourn and Trimley St. Mary having
furnished most of the specimens that were found. Many of these
were taken into Felixstowe by the finders, and disposed of
there, and have been labelled as if from that locality.
On the opposite bank of the River Deben at Sutton, a very
fine exposure of Newbournian and other Crag was once to be
seen. Prestwich, in his paper, gave a detailed plan of the hill
of Coralline Crag, which is shown to be surrounded by the Red
Crag deposits. My brother and I, in the joint paper already
referred to, gave at full length our reasons for rejecting the
accuracy of the plan and the identity of the contents of the
pits seen on it. It was the difference in the faunas of these
sections that led us to the separation of the Crags.
The succession theory helps us to place some beds whose
geological horizon has never been satisfactorily located, the Felix-
stowe Cliffs, Bawdsey, and some places along the left bank of the
Deben, Pettistree Hall, Sutton, and Shottisham, in which the
fossils have much in common with the Newbournian zone, and
equally so with the Butleyan zone, to be next discussed, occupying
as it were a middle place or sub-zone (Bawdseyan). The fossils
are in a better condition, the stratification more regular (a
mussel scalp extending for some yards, the shells in position,
is a very clear example), and the deposits are, if not wholly so,
practically free from the great mass of detritus characteristic
of the Newbournian zone. This seems to shew that the great
denudation or breaking up of the older formations had ceased,
the sea opening up to the north and closing in to the south.
The lists of fossils from Felixstowe and Bawdsey, in Mr.
Wood's Supplement to the Crag Mollusca, and mine from Shottis-
ham Creek5 (pit G. of Prestwich's plan), give a fairly complete
summary of the life of this period. From this I have collected
about 150 species.
The Upper or Butleyan Crag occupies the country from
Alderton and Hollesley to Butley and Chillesford, possibly
eventually to Woodbridge. Here, however, the Mactra beds may
belong to the last series of intermediate beds.
5 "On the Butley Crag Pits," Geological Magazine, 1871, p., 456.