BRITISH OYSTERS : OLD AND NEW. 207
of fine examples of a nearly extinct type of oyster, obtained by
him from an early oyster-pond of the Roman period at Hampton,
near Herne Bay, Kent. The shells occurred in pairs, of varying
shapes, some being oblong (plate xv., fig. 13), others long (plate
xiv., fig. 11). The lower valves are strongly costate, broadly
ribbed; upper valves marked with strong growth-lines, margins
approximate plain, showing closely appressed laminations,
coloured on the edges by a reddish or purple tinge, a feature
very unusual on the East Coast.
I have obtained it from the Dovercourt marshes, from
mediaeval buildings at Ipswich, and Sir James Smith added
others to the Linnean Collection in 1770 from similar dwellings
in Norwich. Length of oblong type figured 80 mm., breadth
100 mm., of longer shell length 130 mm., breadth no mm.
The oblong form is extended beyond the confluent margin
of the inhabited portion of the shell by a superfluous growth of
shelly matter.
OSTREA FOULNESSII sp. nov.
The only other tinted shells I know of on the Eastern coast
came to me from Foulness Point, on the Essex coast. These
shells are native to the ground they occur on, and are mostly
adherent to the rock by the greater part of the under valve,
which hides the sculpture on the specimen figured (plate xv., fig.
14). This is seen to be rather more closely ribbed than usual. The
shells are not large, and are very variable in their outline, due
to their environment ; valves usually compressed the fluting
or folds tinged purple or pink; the margins of the valves touching
each other. My largest specimen is about 100 mm. long, by
50 mm. broad.
The most plentiful of the Selsey oysters are of the lamellose
type (plate xv., figs. 15 and 16), but there are others which
vary from these considerably in their outline and structure, being
long subtrigonal with well-marked umbones showing traces of
former attachments. In two of these the costae are fine and
delicately imbricated, the largest being 120 mm. long, the
other being a coarser build and with broader ribs and with
concentric growth marks. I do not know any living shells to