98 
JURASSIC, OR 
range. That species, however, shows nothing of the curious- 
l} r -fiattened umbones, a character but ill-expressed in our 
figure. 
CUCULLiEA LEIONOTA—A 7 . Sp. 
Plate 23, fig. 4. 
Above 2 inches long, and broad, of a very regular 
transverse oval shape, only a little more pointed behind than 
in front, and with but a slight posterior ridge. The whole 
shell is smooth, even, gently convex, and regular in shape: 
and for the genus remarkably so. 
The beak is placed rather behind the anterior third: it is 
small and little prominent. The anterior side is regularly 
convex, and rounded from beak to ventral margin, without 
depression for a lunette, or any sinus. The front margin 
regularly rounded. The posterior side slightly more pointed 
than the anterior, but regularly rounded, nevertheless, into 
the hinge-margin. A low blunt diagonal ridge marks off the 
posterior side. Hinge plate moderately broad, with about 
three long diverging posterior, and three or four anterior, 
teeth. Pallial line at some distance from the margin. 
The surface is marked only with a few lines of growth, 
antiquated on the posterior slope. Except this, the shell is 
quite smooth; free even from microscopic lines. And this is 
so rare in the genus, that there is no occasion to compare it 
with other species. 
ANATINA VAGINULA.-A 7 . Sp. 
Plate 23, fig. 5. 
A fragment of an elongate bivalve, with a strong sub¬ 
cardinal ridge near the anterior end, would have suggested 
several affinities, either of which might be a true one. But 
the Abbe Stoppani, in his work, already quoted, has figured 
an Ana t in a from the Upper Trias, which sets the matter at rest. 
