232 
VENUS. 
wards the sides, especially the anterior side, into irregular 
wart-like knobs; these ridges have generally their outer- 
surface and the interstices transversely striate, and towards 
the hinge the spaces between the ridges are striate longi¬ 
tudinally : beaks curving much to one side, with a broad 
heart-shaped depression on the posterior slope ; the ante¬ 
rior slope of one valve turns suddenly in, and is finely striate 
longitudinally, and marked with brown transverse streaks: 
color dirty white, more or less tinged with rufous-brown ; 
inside smooth, white, with the margin finely notched i 
length two inches and a half; breadth rather more. 
Young shells are flatter, much thinner, not much tuber- 
cled, broader in proportion to the length, and the spaces 
between them are entirely crossed by fine lines. A com¬ 
parison of the young shell, or what has been called V. can- 
cellata, with one of full growth, will instantly bring con¬ 
viction of their identity, especially if one of intermediate 
size be interposed. With the former, Mr. Dillwyn has 
joined the V. laminosa, a shell of a totally different figure 
and appearance, and even the V. Casinato form his V. can- 
cellata. 
English, Irish arid Scotch coasts, v. v. 
3. Venus Casina. Caslna Venus . 
Lister , pi. 28G. f. 123— Pennant , pi. 5/. f. 2 —Da Costa , 
pi. 13. f. 4, left hand fig.— Linn. Trans, viii. pi. 2. f. 1. 
Shell thick, convex, white, with more or less of a deep 
rufous-brown tinge, rounded and not elongated at the an¬ 
terior side, with transverse raised thin ridges, sometimes 
placed in pairs, and curved in a rounded manner towards 
the hinge, but not breaking into tubercles at either of the 
sides, nor striate longitudinally between them near the 
beaks : beaks curved much to one side, with a heart-shaped 
depression under them; one valve suddenly sloping inwards 
at the cartilage side, and finely striate longitudinally ; in¬ 
side white. With the margin finely notched : diameter two 
inches. 
Da Costa’s figure is an excellent one, which Maton and 
Rackett have referred to for V. verrucosa, and Dillwyn fer 
V. cancellata. 
On the Scotch coasts, and Bray in Ireland, v. v, 
4. Venus 
