Pvn H,i I'UitlS

250 LVQimi)m>
Molluscorum litora Scandinavian occidentalia habitan-
tium/ is not uncommon on the coasts of Norway and
Sweden; but it has not been found in our seas. I
venture to regard it as a large variety of A. flexuosus.
Some remarks will be found on the subject when I come
to treat of the next species.
2. A. Croulinensis $, Jeffreys.
Clattsina Crov.linensis, Jeffr. in Ann. Nat. Hist. vol. xx. p. 19;
p. 122, pi. v. f. 2, a-c (young).
ser. 3. ii.
Shell obliquely oval, tumid, of a moderate thickness,
opaque except in the young state, rather glossy : sculpture,
numerous and fine but irregular concentric strise : colour white :
epidermis slight : margins rounded on the anterior side, as
well as in front, and slightly angular on the posterior side,
which is indented by a double but short furrow : beaks small
and prominent, much more recurved than in the last species,
. almost contiguous and central : lunule indistinct : corselet
narrow but well defined by the upper furrow : ligament slight,
not visible outside ; ligamental groove sloping inwards :
liingel',ie
obtusely curved, occupying not one-fifth of the circum-
ference : hinge-plate rather narrow but thick, almost all of
it lying on the posterior side ; the tooth-like folds are as in
A. flexuosus, but very much stronger and more conspicuous :
inside highly glossy, iridescent, and smooth ; margin thin and
plain: pallial
B. 0-135.
Habitat :
45 to 85 fathoms ;
Skye
scar indistinct : muscular scars oval. L. 0*15.
and Shetland, in muddy sand, from
rare.
This shell, compared with specimens of A. flexuosus
of a similar size and age, is longer and more oblique, as
well as proportionally more solid ; the margin of the
anterior side is curved, instead of being nearly straight
and truncate; the furrows on the posterior side are
scarcelv visible when viewed in front : the beaks are
* From its having been first found near Croulin Island, in the He-
brides.