Pvn H,i I'UitlS

grooved as in other ribbed species
distinct. L. 1-625. B. 1*475.
PECTEN. 63
Var. 1. alba. Shell of a milk-white colour.
: muscular scars rather
Var. 2. Dumasii. Shell smaller and more solid, longer in
valve less convex than the
proportion to its breadth ; upper
lower one and sometimes quite flat or even slightly concave :
sculpture coarse, with 3-10 sharp ribs : ears often unequal,
those on the byssal side smaller than the opposite pair. P.
Dumasii, Payr. Cat. Moll. Corse, p. 75, pi. ii. f. 6, 7.
Habitat :
Rather plentiful in Loch Fyne, and generally
distributed over our northern seas, and southward
as far as the Northumberland coast, in 20-90 fathoms,
rough ground. Var. 1. Loch Fyne and Shetland (Bar-
lee). Var. 2. Hebrides and Shetland. This species is
fossil in the Clyde basin, and in other glacial deposits in
Scotland as well as Norway. It ranges from Finmark
to the iEgean, but it appears not to be so common in
the south as in the north. The variety Dumasii occurs
in the upper miocene strata near Antibes.
P. septemradiatus was added to the British fauna by
the late Capt. Brown in 1835. It is remarkable that
such a handsome and by no means small shell should
have previously escaped the notice of Laskey, Fleming,
Macgillivray, and others of our northern conchologists.
This can scarcely be accounted for by the dredge not
having been used in those days, because specimens are
usually procured from fishermen. They are frequently
caught in the herring-nets, when disturbed on their
feeding-grounds and swimming or flitting
about. I
am not aware that the animal has ever been described ;
and I have unfortunately missed the opportunity of
observing it. Asbjornsen mentions his having taken
which were full of a
specimens in the beginning of May,
milky fluid. The shell is extremely variable in respect
of shape and the number of ribs, as well as of the pro-