125 
VENUS. Linn. 
Gen. Coir. An equivalved rather inequilateral 
bivalve with three hinge teeth in each valve, 
converging towards the beaks ; ligament ex- 
ternal, placed upon the anterior slope. 
EE ee 
Tue shells of this Genus have generally a cordate im- 
pression under the beaks, and their form is more or less 
orbicular or transversely oblong; their edges are often 
crenate; the shell smooth and ornamented with various 
elevations, mostly running in a transverse direction, 
while the colours that so frequently enliven their surfaces 
are placed longitudinally, zigzag, or irregularly, so to 
produce great beauty and much pleasing variety: the 
anterior side is generally more or less defined by anangle 
or the abrupt termination of the transverse ornaments. 
The Genus Venus as defined by Lamarck is dis- 
tinguished from other shells which Linneus included 
under the same head, by Linneus’s own character, the 
number and position of the teeth in the hinge; in confor- 
mity with this I found it necessary to form the Genus 
Astarte of such shells as have only two teeth in each valve. 
Other shells of the Linnean Genus Venus are arranged 
by Lamarck under his new Genus Cytherea, and dis- 
tinguished by an additional tooth separated from the rest 
and placed under the lunula or posterior slope. But as 
there is no other difference, he seems himself to doubt the 
propriety of the separation, and I am unwilling to adopt 
it because the additional tooth is sometimes very small 
and seldom possesses the regularity of the other teeth. I 
have figured already two species of genuine Venus, lineolata 
and plana tab. 20. [have also figured two others as of this 
Genus, V. equalis and angulata, tab. 11 and G5, but they, 
together with Venus [slandica, which they muchresemble, 
differ from Lamarck’s character in the disposition of the 
teeth under the beak, and possess in one valve, besides 
them, a lamellar elongated tooth within the anterior 
side; these may, perhaps, hereafter form a good Genus. 
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