BIVALVIA. 141 
Shell small orbicular, equilateral, convex, concentrically striated, stricze close-set, 
and numerous ; an ovate impressed Junule ; lateral teeth distinct; margin crenulated. 
Diameter, +. of an inch. 
Locality. Coralline Crag, Sutton. 
This species is exceedingly abundant, but restricted, as far as I have seen, to one 
locality, where, from the prominence of the lateral teeth, the valves are sometimes 
found united. 
Our shell is furnished with one cardinal, obtuse, triangularly formed tooth in the 
right valve, and a distinct and distant lateral tooth on each side: in the left valve 
are two cardinal diverging teeth, with a triangular space between them, also two 
lateral teeth: anterior muscle mark large, but not very narrow. The striz upon 
the exterior are rounded, and about as broad as the spaces between them, and 
the posterior side is marked with an obscure ridge, produced by a slight inflection of 
the margin on that side, and at the ridge the strie often bifurcate. being less 
numerous upon the inflected portion. 
A shell in my Cabinet from Bordeaux, which I presume to be Lucina dentata, Bast., 
appears to differ from the Crag shell in several characters, it is more tumid, rather 
wider in a contrary direction to our shell, and is more finely striated externally, 
and has not so distinct a ridge on the posterior side; the anterior tooth is the 
more prominent in our shell, and the inside has fine radiating strie, which I do 
not observe in Basterot’s species; in ours the ligament is wholly external, placed 
on a prominent fulerum; in the Bordeaux shell it is internal, placed obliquely beneath 
the umbo, and if I am right in the species, belongs to the genus Loripes. 
Lucina striatula, Nyst, may possibly be the same as our shell, though it is distinctly 
stated by that author to have the margin free from crenulations, but, judging from the 
locality, his shel] may perhaps belong to the older or Bordeaux species. 
From the description and figure of the American fossil by Conrad, I presume his 
shell to be the same species. We have seen the preceding (Jorealis) to have a range 
from the Mediterranean to the Coast of the United States, and there is great proba- 
bility that the fossil from the Upper Tertiaries of that side of the Atlantic is identical 
with our own; it is somewhat singular the author should have chosen for his shell 
the same name under which the Crag species had passed in my Catalogue, and the 
coincidence is perhaps the more remarkable, the American fossil having been obtained 
from Suffolk, in Virginia. 
3. Lucina pEcoraATA, S. Wood. Tab. XII, fig. 6 a, 4. 
Luctna sauamosa? Goldf. Pet. Germ., vol. ii, p. 230, t. 147, fig. 3, a, 6. 
Spec. Char. Testd transversd, ovatd, inequilaterali, crassd, striis radiantibus, et 
decussantibus ornatd ; lunuld magna, lanceolata ; cardine unidentato, dentibus lateralibus 
perspicuis : umbonibus prominentibus. 
