Pvn H,i I'UitlS

336 VENERIDyE.
teeth ; margin very finely toothed or crenuiated in every part
sea?- broad and
except on the dorsal or ligamental side : pdllial
sinus : muscular scars
polished, with a narrow and not deep
distinct, semioval and polished, marked by a few symmetrical
lines, which denote the successive shiftings of the muscles.
L. 0-8. B. 0-9.
Yar. 1. radiata. Shell beautifully marked with many reddish-brown
rays, which sometimes are alternately large and
small, or double.
Tar. 2. raricostata. Shell smaller and having proportionally
fewer ribs.
Habitat :
In every part of the British seas, among
nullipores and in gravelly and sandy ground, from the
shore to the deepest water. The first variety occurs at
Exmouth and Falmouth, in Bantrv Bav, off Arran Isle
(co. Galway), and in Shetland. The other variety is
from the west of Scotland. This common but pretty
species is a member of our newer tertiaries, having been
recorded by Smith from a postglacial deposit at Ayr,
and bv Searles Wood from the Mammalian and Red
Crag. Havosund, near the North Cape, appears to be
in the highest, and the iEgean in the lowest latitude
where it has been noticed. It is extensively diffused over
the intermediate area. M 'Andrew found it living be-
tween tide-marks at Gibraltar. According
to Brocchi
and Philippi, it is a fossil of the Italian tertiaries.
The animal is inactive, and does not seem to be fond
of exhibiting itself to curious malacologists. In the
( Cornish Fauna '
by
Mr. Jonathan Couch it is stated
that this species, as well as V. gallina, frequently creep
into crab-pots in search of the bait. I should scarcely
have imagined that any bivalve possessed such an extra-
ordinary habit. Some specimens
are more convex than
others, and the shell is now and then distorted. The
crenulations which border the inside margin resemble