Pvn H,i I'UitlS

402 tellinidjE.
of Tellina (e. g. T. donacina) in its cuneiform shape ;
but the dentition is more complicated. The ligament
is placed at the smaller end of the shell, as in all the
other genera belonging to this family. Under the above
circumstances I have thought it best to unite the Dona-
cidce with the Tellinidae, considering
also that we have
only Donax to dispose of.
The habits of the present genus are gregarious, and
usually littoral, although in suitable localities, where a bed
of sand extends out to sea, the Donaces may be found at
some depth. According to M. Pictet it did not make its
appearance until the Tertiary epoch.
Chemnitz called it
Serrula, and Poli Peronaa. Lamarck's genus Capsa is
described as having no lateral teeth, and only differing in
that respect from Donax : the late G. B. Sowerby added
another character, viz. a smooth inside margin,
and in-
stanced our D. politics as one of the types ; but that
species certainly
has lateral or side teeth.
A. Inside margin strongly notched.
1. Donax vitta'tus*, Da Costa.
Guneus vittatus, Da Costa, Brit. Conch, p. 202, pi.
F. & H. i. p. 332, pi. xxi. f. 4, 5, and (animal) pi. K. f. 7.
xiv. f. 3. D. anatinns,
Body elongated, purplish-red or yellow: mantle open for
two-thirds of its extent, thickened at the edges and having a
double margin ; one margin is short, with sinuous or scalloped
edges ; the other and outer one is fringed with three rows of
cirri, the inner two consisting of moniliform white beads of two
sizes, and the outermost or third row having short, close-set,
the cirri become longer and
fine filaments of the same colour ;
side : tubes trans-
stronger as they approach the posterior
parent, of equal length, and when fully exserted not more than
incurrent tube ornamented with eight lon-
half an inch long ;
gitudinal ciliated lines of an opaque- white colour, which give
* Banded.