Pvn H,i I'UitlS

136 MYTILID^.
bivalve. Mr. Bean kindly sent me a specimen of the
latter, and I described it in the f
of Natural History '
name of Modiola cuprea.
Annals and Magazine
for January 1859 (p. 40) under the
I subjoin the description :—
" Testa ovato-trapezoidea, gibbosa, solidula, nitida, epidermide
prismatica, frdva (antice flava), pilosa vestita, subtus
albida, rugis concentricis raris irregulariter notata; angulo
transversali ex apicibus ad latus posticum oblique decurrente ;
umbonibus obtusis ; lateribus, dorsali rectiusculo elevatiore
postice rotundato, antico abrupte truncato, ventrali convexo
subsinuato antice declivi, posteriore quadrato ; marginibus in-
tegris ; bysso ex filis perpaucis curtis crassulis composito ;
long. -1 lat. 4- unc."
On* ft
But this description is incomplete, inasmuch as
no mention is made of the internal structure of the
hinge. Having succeeded in opening the shell, after
steeping it for a long time in water,
I am now enabled
to supply this deficiency; and the result has compen-
sated for the care and patience bestowed on the operation.
Each valve has on the anterior side of the beak
four small but prominent tubercular teeth, and on the
posterior side the same number of angular teeth, which
are set obliquely and resemble in shape those of Nucula
or Leda. The hinge-line is microscopically but indis-
tinctly notched, as in Crenella and some species of Area.
I do not know if this peculiar arrangement of tuber-
cular teeth on one side and of lamellar teeth on the
other side of the hinge has any parallel in bivalve
shells, unless it be the genus Nuculocardia of D'Orbigny.
The little shell in question is evidently littoral, judging
from the habits of the other species which were found
with it in the bird's stomach. From what coast, or
from what part of the northern hemisphere, it was
brought to our shores, it is almost impossible
to con-
jecture. The animal was preserved in my specimen,