Pvn H,i I'UitlS

348 VENERID-S.
shorter than they have been stated to be in ours, and
diverge considerably; but there is a discrepancy between
the accounts published by Forbes and Hanley on the
one hand, and by Clark on the other, as to the length
of the tubes, and a variation with respect to the extent
of their divergence is shown in the figures of Poli and
Deshayes. The cirri which fringe the orifices of the
tubes appear to be as numerous and conspicuous in the
one form as in the other. Many unnecessary names
have been bestowed on this common species and its
variety laminosa. I have noted ten,
besides those above
mentioned. The V. pallida of Turton is not even a
variety : the outer layers have been dissolved by muriatic
or some other acid; and the types are " doctored" shells,
such as unscrupulous dealers sell to ignorant collectors.
All specimens have longitudinal striae. My description
of the teeth in ordinary examples will explain the seem-
ing peculiarity in the dentition of Montagu's V. laminosa,
as noticed by Forbes and Hanley.
V. dysera of Born and Chemnitz (but not of Linne),
one of the many t( ben trovato " discoveries of Laskey,
is West-Indian. It is the V. cingenda of Dillwyn.
V. granulata of Gmelin, V. Paphia of Linne (according
to modern authors), and V. circinata of Born (V. Gui-
neensis, Montagu) may be classed in the same category
of spurious species. V. subrhomboidea of Montagu is
apparently the adult of Petricola lithophaga, Retz,— his
My a decussata (P. Ruperella, Lamarck) being certainly
the younger state of that shell : this species has not been
authenticated as British, although
it is rather common
in the Mediterranean and the west of France ;
Mr. J.D.
Humphreys's collection of Irish shells contains a specimen
found by him in Cork Harbour, but I have reason
to suspect that it came from a piece of ballast stone.