Pvn H,i I'UitlS

VENUS. 341
in the north of England ; but in these cases the shells
may have been introduced among ballast. That mode
of importing extraneous shells into our sea-ports has
happily ceased, owing to the great
care taken of late
years to prevent the discharge of ballast in or near any
tidal harbour. More mischief was caused to navigation
than to conchology by previous neglect of the above
precaution. V. verrucosa is common in the south and
west of Ireland. Sussex tertiaries (Godwin-Austen) ;
Wexford beds (Sir Henry James) ; Coralline Crag (S.
Wood). It does not appear to inhabit the north of
Europe. South of Great Britain it has been found every-
where, from Brittany to the iEgean and the Canaries, in
2-60 fathoms. Dr. Menke considers a species from
St. Vincent to be identical with ours.
The animal is occasionally eaten in some of the
Channel Isles, and habitually in county Clare. Wein-
kauff mentions that it is sold in the market at Algiers.
V. Casina is its nearest British analogue ; but the present
species may be always recognized by its more
globose form, its coarse and rugged look, the ridges
being nodular or warty, and regularly equidistant (instead
of numerous in the umbonal part and few on the
main portion of the shell), and by the longitudinal stria
being much stronger and more like fine ribs.
Linne compared the shell with his V. Paphia, of which
he unaccountably supposed this might be a smooth
variety. In the '
Gazophylacion '
the " 5
Cornwalle hearte-cockle with rugged girdles/
of Petiver it is called
is the " Clonisse " of D' Avila, and Pectunculus sirigatus
and in its younger state it is
probably the
of Da Costa ;
V. subcordata of Montagu,
It
V. cancellata of Turton's
1
Conchological Dictionary/ and V. Lemanii of Payraudeau.