BRITISH OYSTERS : OLD AND NEW. 193
"can answer for the common forms being found at Cannes."
I have myself recorded it from Biot, near Antibes (Journ. de
Conch., 1870, vol. xviii., p. 351), but in view of McAndrew's very
definite statement I doubt the correctness of my identification.
Still later, when his views had enlarged, Jeffreys (Proc. Zool.
Soc. 1879, p. 555), extended its range from Iceland to Mogador,
the Mediterranean, the Sea of Azov, Nova Scotia and New-
foundland, and, as a fossil, from Scandinavia to Turkey. I
regret to say I cannot agree with him, and to my mind it is
now practically confined to the Celtic Province of Western
Europe, but according to Locard has been acclimatized
in Corsica. It is occasionally imported into Italy and sold
in the Neapolitan fish market4.
Da Costa's shell is from his description a western variety or
type.
Pennant's description is meagre : "It is commonly of an
orbicular form, and very rugged, and so well known that descrip-
tion is needless."
Later historians than Da Costa and Pennant are more explicit.
Montagu (Testacea Britannica, 1803, p. 151), described O. edulis
"as being a suborbicular rugged shell with plates or folds lying
over each other, generally of a brown colour, varying in shape
and size according to the position in which it is found. Some
have very strong thick ponderous shells, others are very thin
with membranous plates, or laminae, obscurely and regularly
striated." The latter I have referred to as O. Devonensis (see
pl. xvi., fig. 20).
OSTREA EDULIS typica.
Shell more or less orbicular, becoming conical or pyriform
where the apex is prolonged ; valves unequal. Upper valve
covered with close-set scales or lamellae, seldom projecting
beyond the margins of the shell which meet each other. Under
valve fine to moderately costate ; ribs interrupted at yearly
growths—colour dull brown. Margins plain. Interior pearly
white or opalescent.
That described by Jeffrey (Brit. Conch., pl. xxi., fig. 1.), may
be taken as a typical shell. This form is most prevalent in the
4 Which particular variety or form McAndrew referred to is not very clear. There are
no shells in his collection at Cambridge of either East Coast or Celtic type. The nearest
approach to it is the delicate and beautiful horn coloured shells which I have named
O. Atlantica.