Pvn H,i I'UitlS

72 PECTINIBvE.
prominent : ears long and drooping, nearly square-set, those
on the byssal side being the smallest, rounded at the corner ;
byssal notch slight: hinge-line straight,
two-fifths of the
breadth of the shell :
cartilage small : ligament so thin as to
be almost : imperceptible hinge-plate broad and smooth; trans-
verse rib slight and scarcely raised : inside pearly, minutely
: muscular scars distinct. L. 0*285. B. 0*3.
striate lengthwise
Habitat : Sparingly occurring, although gregarious,
on all our coasts, in muddy sand at 2-82 fathoms.
Glacial deposits, Fifeshire (Fleming) ; Coralline Crag
(S. Wood). Its distribution extends from Finmark to
the iEgean ; and both in northern and southern locali-
ties it appears to have a considerable range of depth,
viz. 15-200 fathoms, Upper Norway, according to
M fAndrew and Barrett, and 27-185 fathoms in the
iEgean, according to Forbes. Norwegian specimens
collected by Professor Sars are of an extraordinarily
large size.
The animal, as well as the shell,
of this tiniest of
scallops is very lovely. If, when fresh caught, put
it flits about like a bat for a
into a glass of sea-water,
long time, and then fastens itself to the side of the vessel
by a fine and almost transparent byssus.
After a while
it slips its cable and resumes its voyage of discovery,
until it becomes apparently exhausted by the fruitless
search and lies down on one side. My largest specimen
measures only 0'35 by 0375. The breadth invariably
exceeds the length.
For the discovery of this species science is indebted
to the late Capt. Laskey, although he described and
figured it from a right valve only, not having at that
time obtained a perfect specimen. It is the Ostrea
tumida of Turton, P.pygmaus of Von Minister, P. minimus
of Sars, P. Actoni of Von Martens, and P. Foresti
of Martin. The P. Grcenlandicus of Sowerby (P. vitreus