Pvn H,i I'UitlS

Habitat :
Mud
LEDA. 155
and sand, in 20-86 fathoms, on the
Antrim coast, Skye, Hebrides, and Shetland. It is
very local in a recent state, but widely diffused in
glacial beds, and occurs also in the Coralline Crag.
Many conchologists have noticed it as an arctic and
Scandinavian species ; Danielssen and Asbjornsen say
it is found on the Norwegian coast at depths varying
from 10 to 140 fathoms, and Malm on the coast of
Sweden in 30-53 fathoms. The only southern habitat
that I am aware of is Naples, where Scacchi is said
(according to Philippi) to have taken it. It is a tertiary
fossil in Siberia and Sicily.
Some specimens are shorter and more gibbous than
others. Owing to the semitransparency of the shell,
the teeth are distinctly
visible outside the hinge-line.
Philippi named this species Nucula tenuis, before he
was aware that Goldfuss had described it, or that Mon-
tagu had already used that name for another species.
Mr. James Smith called this species Nucula gibbosa,
and Moller N. lenticula. The Yolclia abyssicola of Torell
and Sars is probably a variety of the present species.
The Y. lucida of Loven seems different.
B. Shell triangularly oblong, transversely ribbed, with two
ridges extending obliquely from the beak in each valve
to the posterior extremity, which is truncate and somewhat
open : teeth set in a herring-bone fashion.
2. L. mintj'ta*, Miiller.
Area mimda. Mull. Prodr. Zool. Dan. p. 247, no. 2985. L. cav.data,
F. & H. ii. p. 226, pi. xlvii. f. 11-13, and (animal) pi. P. f. 2.
Body oblong and pear-shaped, greyish-white: mantle fringed
or denticulated at its posterior side by a row of five very short
* Small.