Pvn H,i I'UitlS

328 veneridjE.
anteriorly, but as they approach the posterior
end become less
pronounced and are resolved into dentations : tubes short,
scarcely protruding beyond the shell, united, of much the
same size, rufous around the orifices ; the upper orifice is
almost plain or has a few scalloped points ; the lower orifice
has eight short dull-rufous cirri :
gills pale brown :
palps
short and triangular, strongly striated transversely within,
and less so on the outward surface :
foot very large, occupying
nearly the ventral range, and always presenting itself as axe-
the heel is rather slender and bluntly pointed, but the
shaped ;
rest of the foot can sufficiently protract itself to represent a
thick, short, strong, broad linguiform organ ; its pure white
colour is relieved by beautiful vertical lines of brilliant snow-
white. (Clark.)
Shell almost circular, compressed, solid, opaque, rather
numerous flattened concentric laminae which
glossy : sculpture,
are imbricated or fold backwards, and become closer and irregular
at the sides ; the surface is also covered with still more
numerous microscopical longitudinal
striae which exhibit the
inner texture of the shell : colour yellowish-white, usually
variegated with rays or zigzag streaks of reddish-brown,
purplish-red, or pink of various shades, which are occasionally
broken and sometimes present the appearance of white rays
on a dark ground : epidermis thin, yellowish, only observable
in young specimens, as it is rubbed off in the adult by the
continual friction of sand : margins rounded on all sides except
below the beak, where the lunule is excavated ;
the j)osterior
side has a blunt angle in the middle, and the anterior side
appears high-shouldered and also forms an obtuse angle where
the lunule ends : beaks separated, considerably and somewhat
obliquely recurved : lunule heart-shaped, defined by a
deeply impressed line, coarsely striated in an oblique direction,
usually of a purplish hue ; lips prominent or : pouting corselet
narrow, but deep: ligament rather long, horncolour, sunk
within the corselet : hinge-line rounded or obtusely angled :
hinge-plate thick, broad, and flexuous : teeth, in the right Yalve
four cardinals, that on the anterior side being small and tubercular,
and the other three laminar and divergent (the middle
one cloven or double) ; in the left valve are three divergent
laminar cardinals, the posterior one being double; lateral
tooth in each valve long, and more like part of the hinge-plate :
inside polished and slightly freckled, sometimes stained with
purple on the posterior side ; margin bevelled : pattial scar