225 
bivalve, with two oblong, unequal, and diverging hinge teeth, in the 
superior valve, and two oblong corresponding pits in the other valve : 
the cartilage interior, and two muscular impressions. 
This shell is thin, and semi-transparent, the dorsal suture straight, 
prolonging and widening itself at one end. One valve is convex, and 
the other flat. The inequality of the valves separates this shell from 
the Tellens. Tellina inequivalvis, Linn, is referred to this genus, of 
which no fossil shell has been mentioned. 
CXLIX. Gorbula. A subtransverse, inequilateral, inequivalved 
bivalve, with rather prominent and incurvated beaks : a single conical 
recurved hinge-tooth in each valve ; the cartilage internal ; two lateral 
impressions. 
This is exceedingly distinct from every known genus. The beaks 
of these shells are particularly tumid and curved inwards, and one of 
their sides is much more lengthened and thin than the other. Lamarck 
refers the shells Yol. x. Tab. VJ2 , No. 1668 to 16/1, in Chemnitz’s 
work, to this genus. He also describes eight fossil species found in 
the environs of Paris : C. gallica, C. rugosa, C. striata, C. angulata, 
C. anatina, G. argentea, and C. cancellata. 
C. gallica is the largest of these, and that in which the characters 
of the genus are most decidedly shown : it is generally about an inch 
and a half wide. M. Lamarck observes, of this shell, that it is trans- 
verse, oval, tumid, and very singular, from the lower valve being 
smooth, and having its hinge-tooth originate beneath the edge, and 
curve up towards the beak ; whilst, in the upper valve, longitudinal 
strife are evident, and the tooth proceeds from the edge of the valve, 
is compressed, and stands up perpendicular. It is not, however, cer- 
tain whether these may not be valves of distinct species, since they 
have always been found separated. 
Plate XVI. Fig. 2, represents the inside of the smooth valve of C. 
gallica, in which may be perceived the hinge-tooth, approximating to 
the beak. 
VOL. III. 
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