Pvn H,i I'UitlS

arcidjE. 137
and does not seem to have undergone the least decom-
position; and the shell still retains its original colour
and gloss. The species has not been noticed by any
other writer, nor have I detected anything approaching
it in the extensive collections made by Dr. Torell on
the coasts of Iceland, North Greenland, and Spitzbergen.
There is some doubt as to the kind of bird from whose
crop
the shells were extracted. Mr. Bean asserts that
that it was a Sanderling. Mr. Roberts is equally posi-
tive that it was a Brent-goose ; and he supports his state-
ment by the following domestic anecdote. Having
heard that a Brent-goose was excellent eating, he de-
pended on this bird for his Sunday dinner; but, to
his disgust, when his wife was preparing it for the spit,
it smelt so very " loud," that bread and cheese had to
be substituted. He attributed the smell to the decaying
Ulva on which the bird had fed, and among which
were the shells he had given Mr. Bean. Mr. Roberts
therefore had good reason for remembering what bird it
was that caused so much pleasure to Mr. Bean, but disap-
pointment to himself. Several specimens of this singular
bivalve were taken on the above occasion. It
is figured in Sowerby's Illustrated Index to British
Shells, pi. 7.1 11.
Family VI. AR'CID^, Lowe.
Body thick, corresponding in shape
with the shell : mantle
open in front, but in some genera forming a single fold or two
tubes at the posterior end :
gills two on each side, arranged in
pairs :
foot shaped like a disk, worm, axe, or tongue, capable
of burrowing, creeping, or spinning a byssus.
Shell triangular, oval, wedge-shaped, round, oblong, or
rhomboidal, equivalve, inequilateral : epidermis thick :
ligament
external ; certain genera have an internal
cartilage
in