Pvn H,i I'UitlS

PECTEX. 67
cures its food, viz. by rapidly opening the valves of its
shell and clapping them together with an audible noise
ten or twelve times in succession. It then kept them
wide open and for a much longer time than suited the
patience of the great zoologist. By this violent agitation
of the water a fresh supply of animalcula may be
brought
to its insatiable maw. He adds that it can
squirt the water out of a vessel half an ell high ;
but I
have never seen it perform such an extraordinary feat.
The jet of water would be at least fifty times the length
of the animal.
A slight and pardonable liberty has been taken in
changing the original spelling of the specific name from
tiger inus to tigrinus. This shell was called P. parvus
by Da Costa, P. domesticus (used of course in the sense
of native) by Chemnitz, and P. obsoletus by Pennant.
6. P. Test^:*, Bivona.
P.. Testes. (Bivona) Philippi, Moll. Sic. i. p. 81, t. v. f. 17. P. furtivus,
Lot. Ind. Moll. Scand. p. 31.
Shell somewhat resembling P. tigrinus in shape, but
rounder and much more depressed, rather thin and glossy :
sculpture, minute longitudinal and transverse striae, which are
arranged as in the last species, but they are more regular and
never forked ; they are deeply punctured at the points of
intersection ;
sometimes there are also from 30 to 35 delicate
ribs, which become scaly or prickly where they are crossed by
the transverse striae: colour yellow, orange, brown, purple,
pink, or occasionally white, usually diversified by streaks, rays,
blotches, spots, diagonal lines, and other markings of the above
hues : margins rounded in front, and forming an arc of twothirds
of a circle in consequence of the lateral slopes towards
the beaks commencing higher up than in P. tigrinus ; byssal
slope finely toothed : beaks prominent but not much raised :
ears unequal, those on the byssal side being about twice as
large as the other pah ; all of them have several fine ribs,
• * Named in honour of S r . Testa, a conchologist at Panorino in Sicily.