Pvn H,i I'UitlS

KELLIA. 225
1. Kellia suborbicula'ris #, Montagu.
My a saborbieularis, Mont. Test, Brit. p. 39, tab. 26. f. 6. K. suborbicularis,
F. & H. ii. p. 87, pi. xviii. f. 9, 9 a & 9 b, and (animal) pi. O. f. 4.
Body white and nearly transparent : mantle protruding be-
yond the shell in front, and having its margin fringed with a
few thornlike or triangular tentacles : incwrent tube varying
in length and diameter even in the same individual ;
its oriiice
gills pale yellow and
plain, but uneven : excurrent tube short :
striated :
lips thick, strong, and coarsely striated : foot com-
pressed, flexible, and hyaline.
Shell usually globular, but sometimes inclined to an oval or
triangular outline, ventricose, rather thin, and more or less
glossy: sculpture, distant lines of growth, and close-set and
irregular concentric striae, besides some slight longitudinal
lines : colour milk-white, with a faint tint of yellow : epidermis
thin and beautifully iridescent: margins somewhat truncate
but obliquely rounded at the larger or posterior end, a con-
tinuous curve being formed by the ventral and anterior sides :
beaks circular and calvciform, incurved and twisted towards
the anterior or smaller end, close together, but not contiguous ;
they are placed nearly in the centre of the dorsal margin, and
there is a depression or incomplete lunule formed below them :
hinge-line curved, occupying nearly
ference :
cartilage triangular, yellowish-brown,
one-third of the circum-
attached to the
hinge-plate close to the inner margin of the dorsal side, and
doubled on itself : hinge-plate narrow, but strong : teeth, in the
right valve two strong laterals, the one on the anterior side
being at first erect and resembling a cardinal tooth, and then
(as in Montacutaferruginosa) becoming laminar and attenuated,
that on the posterior side being obliquely triangular ; in the left
valve a recurved cardinal tooth, and two laterals similar to
those in the other valve, the cardinal and anterior lateral form-
ing a double tooth for the reception of the corresponding lateral
in the right valve ; dental sockets deep : inside like frosted
silver, with a slight prismatic lustre : pallial
scar indistinct :
muscular scars large and conspicuous. L. 0*4. B. 0-45.
Var. lactea. Shell somewhat compressed and oval, of a
thinner texture and rather more glossy ;
front margin nearly
straight, and dorsal margin raised more to a level with the
* Nearly globular.
L O