106 DIMY ARIA. TELLINA, 
bones small and incurved, two cardinal and two lateral teeth 
in each valve, the posterior one placed nearer to the cardi- 
nal teeth than the other, which is rather remote from the 
umbones, and situate near the termination of the ligament: 
two lunulate muscular impressions in each valve, simple, 
somewhat oblong in form, and placed close behind the um- 
bones ; pallial impression entire, and destitute of a sinus. 
Ligament external, the parts to which it adheres forming a 
deep groove when the valves are closed. 
Corbis levis. Plate IX. fig, 17. 
The shells of this genus are somewhat allied to the Lucinez, but may be dis- 
tinguished by their more oval form, by the simple, rather oblong muscular 
impressions: they are also something like the Tellinz, but are destitute of the 
fold of the anterior margin of that genus; some species of Cytheree and 
Venus, resemble Corbis, but the lateral teeth, and entire pallial impression, 
will at once distinguish them. 
Only one recent species of this genus is known, which inhabits the Indian 
Ocean. Lamarck describes two species, from the newer formations above the 
Chalk, at Grignon and Granville in France. 
Genus XXXVI.— TELLINA. — Linneus. 
Generic Character. — Shell compressed, transverse, sub- 
equivalve, inequilateral ; posterior side usually rounded ; 
the anterior somewhat produced, or beaked and angular ; 
anterior ventral margin with an irregular flexuosity ; gene- 
rally with two cardinal teeth in each valve, but only one in 
some instances, usually two lateral teeth in both valves, but 
sometimes only one, and for the most part remote from the 
primaries ; two distant muscular impressions; pallial im- 
pression with a very large sinus: ligament external. 
Tellina patellares. Plate IX. fig. 29. TJ. ovata. Plate 
VIII. fig. 9. 
Section 1. Shells transversely oblong; as in T. Spen- 
gleri and rostrata. 
Section 2. Shells ovate, with a rough exterior, as exem- 
plified in T. Lingua Felis. 
Section 3. Sheils nearly orbicular ; as T, carnaria and 
scobinata. 
Section 4, With one valve more flattened than the other, 
as in 'T. opercularis. 
Section 5. Both valves remarkably convex, as in T. 
lacunosa. 
The irregular fold in the anterior margin, is a striking characteristic of this 
genus, 
