This genus differs but little from the Donax; its species are numerous,
especially in the seas of hot countries; they are found sunk deep in the
sand.
There are but few genera that can vie with the Tellina in beauty,
variety, or number; some are smooth and polished, some are remarkable
for their beautiful radiations, and others are covered with minute striæ
and undulations; occasionally the whole surface is covered with
imbrications or scales.
They are produced abundantly in almost every sea and in many rivers, but
the finest species are found in the pearl-fisheries of Ceylon.
The usual form of the Tellina is broad at one end and gradually tapering
towards the other. It derives its name from the Greek word τελειω, to
bring to a termination.
Shell of variable form, generally striated longitudinally and very
compressed; equivalve, more or less inequilateral; anterior side longer
and more rounded than the posterior; offers a flexuous plait or twist at
the inferior margin; summits little marked; hinge similar; one or two
cardinal teeth; two distant lateral teeth, with a pit at their base in
each valve; ligament external.
Tellina radiata.
T. unimaculata.
T. semizonalis.
T. maculosa.
T. virgata.
T. staurella.
T. crucigera.
T. Spengleri.
T. rostrata.
T. lutirostra.
T. elliptica.
T. albinella.
T. margaritina.
T. strigosa.
T. planata.
T. punicea.
T. depressa.
T. pulchella.
T. fabula.
T. tenuis.
T. sulphurea.
T. foliacea.
T. operculata.
T. rosea.
T. chloroleuca.
T. remies.
T. sulcata.
T. crassa.
T. lævigata.
T. linguafelis.
T. rugosa.
T. lacunosa.
T. gargadia.
T. pristis.
T. multangula.
T. polygona.
T. capsoides.
T. exilis.
T. donacina.
T. nitida.
T. scalaris.
T. psammotella.
T. striatula.
T. scobinata.
T. decussata.
T. Brasiliana.
T. obliqua.
T. umbonella.
T. deltoidalis.
T. nymphalis.
T. solidula.
T. bimaculata.
T. sexradiata.
T. ostracea.
_T. radiata._ The radiated Tellen. Pl. 8, fig. 5.
Shell elongated; posterior side shorter and more narrow than the
anterior.
_T. foliacea._ The foliaceous Tellen.
Species transversely oblong; upon the edge of the front side of either
valve are rows of serrated teeth, running from the apex to the margin.
_T. bimaculata._ The double-spotted Tellen.
Species orbicular, easily known by answering to its common name.
_T. fabula._ The false Tellen.
Shell very thin, pellucid, and oval; yellowish colour, darker towards
the umbo, which is nearly central, pointed and turned a little to one
side; anterior side slopes to an obtuse point; posterior side large and
rounded; hinge with three teeth in one valve and two in the other.
_T. scobinata._ The rasp Tellen.
Species oval or sub-orbicular, sub-equilateral.
_T. donacina._ The Donax-like Tellen. Pl. 9, fig. 5.
Sub-oval, flattish, semi-striated and semipellucid; hinge with two teeth
in one valve and one in the other; pale yellow, radiated longitudinally
with pink.
_T. depressa._ The depressed Tellen.
Oval, flat, pointed at the smaller end and slightly reflected; pale
yellowish colour, faintly striated concentrically; covered with a pale
brown epidermis.