Pvn H,i I'UitlS

390 TELLINID^E.
== Macroma tenera, Leach = T. proximo,, Brown = T.
sordida, Couthouy, may be classed with Hypothyris
psittacea, Pecten Islandicus, Astarte crebricostata, and
A. borealis as having long ago existed in that part of
the Atlantic which then covered the greater part of the
British Isles; but all of them are now extinct in our
seas. I have dredged valves of T. calcarea, but always
in a semifossilized state (although retaining part of the
epidermis), among the Hebrides and Shetlands; M'Andrew
has taken similar specimens in Loch Fyne ; and
Professor Macgillivray mentions that one was brought
up by a fishing-line off Aberdeen. This species survives,
however, on the Danish coasts of the Baltic, and northwards
to Spitzbergen, as well as on the shores of Asia
and America from Behring's Straits to Massachusetts.
It is one of the shells most characteristic of " glacial 9
deposits, and occurs in every tertiary bed up to the Red
Crag. Its name ought always to be associated with
that of the veteran geologist James Smith of Jordan
Hill, who was the first to detect the remains of an
Arctic fauna in this country. This was a quarter of
a century ago; and we can even now understand the
delight with which the discovery was hailed by scientific
men, including of course Edward Forbes, whose pithy
saying on the occasion—" Conchology is ris' "— will not
easily be forgotten.
T. remies of Linne (T. fausta, Pulteney), T. reticulata
of Linne (T. proficua, Pulteney), T. lineata of Turton
(T. BraziRana, Lamarck), T. bimaculata of Linne, and
T. similis of J. Sowerby are tropical species, and have,
from accidental mistakes as well as from ignorance of
the laws which regulate the geographical distribution
of the Mollusca, been considered indigenous
to this
country. There is a greater probability that the T.