TELLINID. 171 
TELLIDORA, Morch, 1851. 
Distr.—2 sp. W. Coast of Central America. Fossil, 1 sp. 
Pleistocene; So. Carolina. TZ. Burnettii, Brod. (exii, 75). 
Shell subtriangular, rounded below, very inequivalve, right 
valve concave, left valve slightly convex ; concentrically plicate, 
the plicze forming teeth on the lateral margins; beaks angular, 
inclined anteriorly ; two cardinal teeth in one valve, one in the 
other; two lateral teeth in each valve. 
GASTRANA, Schumacher, 1817. 
Syn.—Fragilia, Desh., 1848. Diodonta, Desh. 
Distr—5 sp. Norway, britain, Mediterranean, Black Sea, 
Senegal, Cape. G. fragilis, Linn. (exii, 76, 77). Fossil. Mio- 
cene—; Britain, France, Belgium. 
Shell equivalve, convex, with squamose lines of growth; car- 
dinal teeth two in right valve, one bifid tooth in left; pallial 
sinus deep and rounded; umbonal area punctate; ligament 
external. 
Animal with the mantle open in front, its margins fringed ; 
siphons elongated, slender, separate, unequal, orifices with cirri; 
foot small, compressed, linguiform ; palpi large, triangular ; gills 
unequal, soft, finely striated. 
Gastrana inhabits shallow water, boring in mud and clay, and 
not traveling about like the Tellens. 
Maca, A. Adams, 1860. + Setlnung ta Rees 
Distr.tm. inquinata, Desh. (exii, 78). Supe V. Breqerert Hasday 
Shell suborbicular, rather solid and inflated, posteriorly with 
a moderate ridge, nearly equivalve; the beaks are prominent, 
the ligament situated in a deep groove; the hinge with two very 
strong cardinal teeth in each valve. 
QuENSTEDTIA, Morris and Lycett, 1853. 
Dedicated to Prof. Quenstedt, paleontologist, of Wurtemburg. 
Syn.—Arcomya and Mactromya (in part), Agassiz. 
Distr.—3 sp. Oolitic; England, France,Germany. Q. oblita, 
Phil. (cxii, 98). 
Shell oblong, equivalve, moderately solid, umbones nearly con- 
tiguous, hinge with a transverse cardinal tooth in the left, and 
a corresponding pit in the right valve; ligament external, placed 
in a long, narrow groove, pallial sinus small. 
Only a few Jurassic species have as yet been referred to this 
genus; its systemic position is doubtful. 
Lucinopsis, Forbes and Hanley, 1848. 
Syn.—Lajonkairia, Dest, Mysia, Gray. 
Distr.—6 sp. Europe, W. Indies, W. Coast of South America. 
L. undata, Pennant (exii, 79). 
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