Pvn H,i I'UitlS

MACTRA. 421
ral teeth of the present species ; it is analogous
to the
variety elliptica of M. solida. Mr. Alder also mentions,
in his (
Catalogue of the Mollusca of Northumberland
and Durham/ " a thinner variety from deep water." M.
subtruncata is not uncommon in our newer tertiaries as
far back as the Red Crag. It ranges from East Finmark
(Danielssen), throughout the North Atlantic, to
Gibraltar (M {
Andrew),
both sides of the Mediterranean
to Sicily (Scacchi and others), and to the Black Sea (Middendorff),
at depths varying in each of these tracts from
the shore-line to 40 fathoms. Brocchi has recorded it
among his Subapennine fossils, and Philippi from the
Sicilian tertiaries j and I found it in the Uddevalla beds,
and at Biot near Antibes in upper miocene strata.
A small is
variety gathered alive at low water in
Lamlash Bay to feed pigs. (Alder.) According to Mr.
Hyndman this species is called the " Lady-cockle " at
Belfast. Mr. Norman says that it goes by the name of
" Aikens " in the Clyde district, where it is frequently
used as bait, and for that purpose either raked up from
the sands at low tides or gathered by the hand when
thrown up on the beach by storms. In Dr. Lands-
borougrVs agreeablv written '
Excursions to Arran '
is stated that the last-mentioned name is " confined to
the Lowlands ; in the Highlands it is called ' Mureck-
baan/—baan signifying the colour, which is white, and
Mureck (it is probable) being the Celtic origin of the
Latin Murex, the shell-fish which yielded the Tyrian
dye or imperial purple." Mr. Norman confesses that
his powers of imagination are at fault, and that he fails
to see any connexion between Murex trunculus and " Mu-
reck-baan." The variety striata attains a much larger
size than the typical form ; I have a specimen nearly
an inch and a quarter long, an inch and a half broad,
it