Pvn H,i I'UitlS

382 TELLINID.E.
5. T. fa'bula*, Gronovius.
T.fabula, Gron. Zoophyl. iii. p. 268, t. 18. f. 9 ; F. & H. i. p. 302. pi. six.
f. 9.
Body clear white : tubes apparently rather longer than in
T. tenuis, which the animal closely resembles (Forbes and
Hanley).
Shell triangularly oval or inclining to oblong, flattened,
thin, semitransparent, glossy, and having a resplendent and
prismatic lustre: sculpture, extremely fine, numerous, and
sharply incised concentric striae, which in the right valve are
at first regular and parallel, but afterwards become stronger,
more remote, imbricated, and flexuous, and slant diagonally
from the upper part of the anterior side towards the front and
posterior margin ; the surface is also covered with much more
numerous and close-set microscopical transverse striae, as well
as with a few slight longitudinal lines, as in the last species ;
the posterior side (and occasionally the anterior side
also)
is
not marked by the larger striae ; the lines of growth are well
defined and sometimes form distinct zones : colour pearl-white
with frequently a tinge of yellow or occasionally of light
orange : epidermis very thin and brilliantly iridescent : mar-
gins not much curved in front, semioval on the anterior side,
flexuous on the posterior side and elongated to a rather sharp
point, from which an obscure ridge runs to the beaks as in
T. tenuis ; the posterior margin is short and obliquely trun-
cate ; the dorsal margin is more or less straight, and slopes to
the upper angle of the posterior side : beaks small, scarcely in-
flected, contiguous, and turned a little towards the posterior
side : ligament as in the last species : hinge-line and hinge-
plate also similar : teeth, in the right valve two erect, small,
deeply cloven cardinals ; in the left valve a cardinal of the
same kind just under the beak, and a much smaller and
laminar cardinal on the posterior side, which diverges from
the other at about a right angle ; each valve has a short in-
distinct lateral on the anterior side : inside chalky-white,
except the line of the pallia!
cular scars, which are polished : pallial
scar and the whole of the mus-
scar as in the last two
species, but larger, with the upper angle extending much further
towards the beak, and infringing on the posterior muscular
impression: muscular scars irregular, but distinct and
visible outside. L. 0-5. B. 0-85.
* A small bean.