Pvn H,i I'UitlS

342 venerid^:.
D. Mantle-tubes disunited only at their openings. Shell oval,
ornamented with longitudinal ribs and cross striae, giving
partly a tubercular and partly an imbricated appearance ;
inside margin notched all round.
7. V. ova'ta*, Pennant.
V. ovata, Penn. Brit. Zool. iv. p. 97, pi. 56. f. 56; F. & H. i. p. 419, pi. xxiv.
f. 2, pi. xxvi. f. 1, and (animal) pi. L. f. 6.
Body suboval, bluish-white interspersed with minute flakes
mantle with thickened edges, which
of milk-white or yellow :
are wavy and fringed by numerous white filaments of different
lengths : tubes very short, of the same length, yellow, united
except at the openings, where they diverge
a little and are
encircled with a row of reddish-brown spots ; lips of orifices
slightly reflected, and surrounded by purplish or pale-yellow
tentacular cirri, each orifice having about 20 of these cirri,
which are alternately long and short, and each cirrus having
a coloured spot at its base ; the excurrent tube is furnished
with the usual anal valve :
gills suboval, very oblique, pale
yellow or brown, more striated on the inner than on the outer
surface : palps short, small, triangular, and striated like the
gills : foot very long, thick, flexible and extensile, protruded
with equal facility on the anterior or posterior side.
Shell triangularly oval, rather solid and opaque, of a dull
aspect: sculpture, 40-50 fine but rather broad ribs, which
radiate from the beak and more or less dichotomize or branch
off in different parts ; these ribs are crossed by about half as
many more raised and thread-like concentric striae, and, in
consequence of their intersection, a series of oblong tubercles
or imbricated scales crests each rib ; the cross striae are often
wanting on the front angle of the posterior side ; the whole
surface is also covered with minute and intermediate trans-
verse striae, which are stronger and more perceptible in the
furrows : colour yellowish, with occasionally a tinge of pink or
orange variegated by irregular blotches, broken rays, or vandyke
markings of red dish -brown: epidermis fibrous and slight :
margins rounded on the anterior side, with a blunter curve in
front, wedge-shaped and somewhat produced at the posterior
end, on which side an obscure angle appears to run from the
beak, and gently sloping on the dorsal side : beaks small and
blunt, rather prominent but not much recurved or separated :
* Egg-shaped.