46 MOLLUSCA FROM THE CRAG. 
This elegant and fragile shell is by no means rare in the Coralline Crag at Sutton, 
but rather less so at Ramsholt. Walton Naze is the only locality in the Red Crag 
from which I have seen it. There cannot, it is presumed, be any doubt about the 
identity of this species, which does not seem to possess even a local variation. 
The strize which ornament this shell are sometimes regular in size, but more often 
possess an intermediate smaller one; there is a very slight opening between the valves, 
near the hinge line on the posterior side, and the valves do not quite close on the 
anterior side towards the ventral margin; hinge line rather short, with a large and 
broad ligamental pit projecting inwards ; a subcircular impression by a large adductor 
muscle towards the convex or posterior side of the shell. 
4. Lima piicatuta, S. Wood. Tab. VII, fig. 4. 
Lima piicatuta. S. Wood. Mag. Nat. Hist., New Series, vol. ii, p. 235, pl. 3, fig. 4, 1839. 
Spec. Char. Testd minutd, inequilaterali, obliqué-ovata, compressiusculd ; costato-striatd, 
striis 14—16 convewis, scabriusculis; anticé rectd, postice rotundatd ; auriculis valde 
inequalibus ; cardine obliquo ; ared ligamenti minutd ; in auriculis dentibus obtusis. 
Shell small, inequilateral, obliquely ovate, slightly compressed; costated or 
striated; strie 14—16 rounded and somewhat scabrous; anterior side straight, 
posterior rounded; auricles very unequal; hinge line oblique; ligamental area 
small, with an obtuse tooth in the centre of the auricles. 
Longest diameter, th of an inch. 
Locality. Cor. Crag, Sutton. 
About a dozen specimens of this shell are in my cabinet, but none of them in very 
perfect condition ; and I have not seen other specimens, since the publication of it in the 
‘Mag. Nat. Hist.,’ to give further assistance in its elucidation. It appears, however, 
to present characters differing from any other species with which I am acquainted, 
and it must, for the present at least, be considered as distinct, and may be more 
particularly described thus. 
The shell is very oblique; the anterior straight, sloping from the umbo with a 
scarcely perceptible auricle on that side; while the posterior is not only rounded, but 
has a comparatively large and projecting ear: it appears to have been able almost to 
close the valve, or at least to have had a very slight gape, as the edge of the shell 
nearly touches all round when laid upon a flat surface with its exterior uppermost ; the 
rays are rounded, slightly scabrous, and numbering about 17 or 18, and these are 
somewhat broader than the spaces between them, which are prettily ornamented with 
elevated ridges, giving it a cancellated appearance. The hinge is rather peculiar, 
the central depression or pit being small and very oblique; and on each side in the 
middle of the auricles is a tooth-like projection with a corresponding depression in the 
opposite valve; a similar character may be observed in other species of this Genus, 
where interlocking prominences and depressions are formed by the animal as an 
