148 SUPPLEMENT TO THE CRAG MOLLUSCA. 
the ‘Crag Mollusca,’ remains of colour in the Crag specimens (which are fragmentary) 
induced me to refer them to the Mediterranean form. JI was misled by Herrmannsen 
(who gave the date of the name J/acha as of 1815 instead of 1835) in using that generic 
name for this shell. Solecurtus antiquatus is mentioned in ‘ Brit. Conch.,’ vol. ui, p. 7, 
and by the author of that work in his list to Mr. Prestwich’s Cor. Crag paper, as a 
Coralline Crag shell; while Mr. Bell, in his paper on the “ English Crags ” (‘ Proc. Geol. 
Association,’ 1872) inserts itas a Red Crag species. The only specimens, however (which 
are all fragmentary), that I have seen from any part of the English Crag belong either to 
strigillatus or candidus. 
Much difficulty seems still to exist respecting the siphonal side of shells of this family. 
In ‘Brit. Moll.,’ vol. i, Pl. I, as 1 before poimted out (‘Crag Moll.,’ vol. 1, p. 254), the 
illustrations for this genus, as well as for other genera in the same plate, show the foot 
protruded on the siphonal or ligamental side of the shell, and the’same misrepresentation 
is repeated in the generic illustrations im Pl. I, vol. ni, of ‘ Brit. Conch.’ The sinuated 
mark in the interior of a bivalve, when it exists (as left by the impression of the 
retractor muscles), is on the side which bears the ligament, and the siphons are protruded 
in that direction, the foot going in the opposite. 
CunreLius Surronensis, 8. Wood. Supplement, Tab. X, fig. 15. 
Spec. char. C. Testa transversa, oblongo-lineari, rectiuscula, laevigata, tenuis, Jraguis, 
antice breviore, rotundato-truncata, postice longiore et latiore ; valde inequi-lateralis, in 
valvula dextra bidentatis, in valvula sinistra tridentatis. 
Length ~ of an inch. 
Locality. Cor. Crag, Sutton. 
Some fragments of this shell have been long in my cabinet, and I had imagined them 
to belong to the same species as that from the Red Crag of Walton, which I had in the 
‘Crag Mollusca’ figured under the name of fenwis, Phil. I now believe these to be 
specifically different, and a perfect specimen having been obtained by Mr. Robert Bell, I 
have figured it as above. The shell differs from pel/wcida in the absence of curvature 
and the broadness of the posterior extremity; it differs also from the Upper Hocene 
species, C. Grignonensis, Desh. (‘ An. sans. vert. du Bas. de Par.,’ Tom. 1, p. 157, Pl. VII, 
figs. 13—15) in its outline, that shell approaching nearer to pel/wcidus than does our own 
shell. A fragment in my possession indicates a length of more than three fourths of an 
inch. 
A specimen of Cultellus from the Aldeby bed sent me by Messrs. Crowfoot and 
Dowson is represented in Tab. X, fig. 14. This seems to be intermediate between the 
Cor. Crag form Sudfonensis and the recent form pellucidus, as the formation from which 
it comes is correspondently intermediate in time. It is therefore not unlikely that 
