MANUAL OF THE MOLLUSGCA. 
Shell minute and roundish oval; beaks straight; cartilage 
long, placed at the shorter end of the shell, contrary to that in 
Kellia ; left valve with a minute thorn-like cardinal tooth; and 
in each valve two remarkably strong lateral teeth. 
The genus is intermediate between Montacuta and Kellia. 
Distribution. ‘* The Lascece usually inhabit the littoral zone, 
where they congregate in vast numbers at the roots of small 
sea-weeds, in the crevices of rocks, and in empty shells. JZ. 
rubra, a British species, is viviparous, and lives as much out of 
the sea as in it. Other species occur in yarious parts of the 
world.”’—Jeffreys. 
Famity X11.—CyYcuapDiIp&.* 
In addition to the genera enumerated in W. M. it, p. 461 
et seq., the following belong here :— 
GALATEA (see p. 486), and— 
FISCHERIA, Bernardi, 1860. 
Dedicated to M. Fischer, one of the editors of the Journal 
de Conchyliologie. 
Type, FE. Delesserti, Bern., inhabiting the rivers of the 
Selboon, W. Africa. 
Shell differs from that of Galatea in the Soubinanias condi- 
tion of the lateral cardinal teeth of the right valve, and by the 
elongated lateral teeth being compressed, as in Cyrena; and 
from Cyrena by its fewer cardinal teeth, depth of the palhal 
sinus, and by the absence of lateral teeth in the right valve. 
Faminy XIII.—CyPrinibDZ.t 
CYPRICARDELLA, Hall, 1857. 
Shell ovate, subelliptical, or subquadrate; concentrically 
striated; hinge of right valve with two cardinal teeth; the an- 
terior tooth beneath the beaks; posterior tooth turned obliquely 
backwards, leaving a triangular pit, which is probably occupied 
by a tooth in the other valve. Anterior cardinal margin with a 
long narrow grooye, apparently for the reception of a slender 
projection of the other valye; posterior side beveled from 
above, edge thin; ligament external, in a deep cavity; mus- 
cular scars distinct, shallow; pallial line simple. 
Fossil, 4 species. Carboniferous. Indiana. 
* See p. 461. + See p. 463. 
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