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CORBIS. Cuvier. 
Gen. Char. A free,, transverse, equal-valved, bi- 
valve, with incurved umbones; two lateral and 
two hinge teeth in each valve, one of the late- 
ral teeth near the hinge, the other remote ; 
attachment of the mantle upon a curved, not 
sinuated line. 
All the species of this genus that have hitherto come 
under observation are transverse shells (that is, they are 
longer in a direction transverse to the position of their 
hinge-teeth) : in common with many other bivalves, the 
umbones are curved inwards, in opposite directions in 
the two valves ; there are two cardinal and two lateral 
teeth in each valve ; that which is on the opposite side of 
the hinge to the ligament, is much nearer to the cardinal 
teeth than the other, which is rather remote, but placed 
near the termination of the ligament. This is external ; 
but the parts to which it is attached form a deep groove 
when the two valves are closed ; when also, a rather ob- 
long cordiform impression immediately behind the um- 
bones may be observed. 
u This Genus was established by Cuvier, and is adopted 
by Lamarck. It is related to Lucina, but may be distin- 
guished from that genus by its muscular impressions, 
which are simple and rather oblong, but neither of them 
produced into an elongated tongue shape ; it approaches 
also to Tellina, but, wanting the fold of the anterior 
(posterior) margin of that genus, it will not be confound- 
ed with it. Not many species of this genus are yet known ; 
the only recent one with which we are acquainted is a 
very beautiful, transversely oval, rather gibbous shell, 
with longitudinal striae and undulated transverse fur- 
rows, and its interior margin is crenulated; it is the Ve- 
nus fimbriata of Linne, the Corbis fimbriata of Cuvier, 
and according to Lamarck an inhabitant of the Indian 
