Pvn H,i I'UitlS

LIMA. 81
2. L. ellip'tica*, Jeffreys.
L. subauriculata, F. & H. ii. p. 2G3 (partly), pi. liii. f. 4, 5.
Body pale orange : Untacula pale pink : foot pale orange.
(F. & H.)
Shell oval or elliptical, convex, slightly and almost equally
expanding towards the sides, thin and glossy, semitransparent:
sculpture, 30-40 fine longitudinal ribs, which become
very faint and indistinct as they approach the sides ; one. of
these ribs, near the middle but more towards the posterior
side, is rather larger than the rest, and a corresponding furrow
is formed inside each valve, appearing outside like an oblique
white line; the ribs are crossed by extremely delicate and
numerous concentric striae, making the crests beautifully
serrate the substance of the shell also ;
exhibits a few diagonal
white streaks or lines, which diverge from the centre to each
side : colour pearl-white : margins broadly rounded in front,
and sloping with a gentle but somewhat flexuous curve upwards
to the ears, much compressed at the sides : beaks extremely
prominent and gibbous, projecting considerably beyond
the hinge : ears triangular, small, erect : cartilage diamond-shaped,
occupying about one-third of the hinge, and
minutely striate across; there is also a very slight and indistinct
ligament on each side of the cartilage : hhuje-line
straight except in the middle, where it is incurved to receive
an ob-
the : cartilage hinge-plate blunt :
cartilage-pit forming
tuse triangle, smooth under ; each ear is a shelving triangular
space confined below by a narrow rib : inside highly nacreous,
and marked by a furrow which runs obliquely down the
middle, and is the reverse or under side of the larger rib on
the outer surface ; it is also
indistinctly grooved by the im-
pression of the ribs ; the front margin is slightly notched by
the edges of those ribs : muscular scar irregularly circular and
distinct. L. 0--55. B. 0*35.
Var. leviuscula. Shell nearly smooth, the ribs being want-
Habitat :
Sandy
mud, in 15-85 fathoms,
off the
Shetland Isles and west coast of Scotland. It is not
uncommon in the latter district. The variety is from
* Elliptical.
E O