92 SUPPLEMENT TO THE CRAG MOLLUSCA. 
Two small specimens of 7. fu/va, imperfect, but comprising the worn apex and larger part 
of the shell, have occurred in the Middle Glacial of Hopton. In the ‘ Crag Mollusca’ I 
stated that this shell was by no means rare in the Cor. Crag, but that is incorrect ; it seems 
rare there, at least, it has now become so. 
DrntaLium REctuM, Zinn. Supplement, Tab. V, fig. 19, a, 6. 
DENTALIUM RECTUM, Gmelin Syst. Nat. ed. 13, pp. 37, 38. 
— — Poli. Test. utriusque Sic., vol. iii, t. lvi, fig. 28. 
—_— ELEPHANTINUM, Desh. Monog. du Gen. Dent., p. 27, pl. iii, fig. 7. 
Locality, Red Crag, Sutton, Waldringfield (Bell). 
The specimen figured was given to me by the late Mr. Acton, of Grundisburg, who 
said it was obtained from the Coprolite diggers at Sutton. 
There are three species described by Linné so closely resembling each other that it is 
difficult to say what character will satisfactorily separate them, viz. D. elephantinum, 
arcuatum, and rectum ; the straight form of the present shell is the greatest, perhaps the 
only distinction. In my fossil the sculpture appears to be generally about twelve large 
costee, with a smaller intermediate one. Mr. Bell gives this from Waldringfield. 
Dentalium costatum, vol. i, Tab. XX, fig. 1 d, from the Red Crag, may probably belong 
to this species. 
DENTALIUM ENTALIS, Zinn. Supplement, Tab. VI, fig. 20. 
DENTALIUM ENTALIS, Linn. Syst. Nat., p. 1263. 
Localities. Cor. Crag, Sutton, and near Orford. Post Glacial, Kelsea Hill. 
The figure above referred to is the representation of two or three fragmentary 
specimens lately found by myself in the Coralline Crag at Orford and Sutton, and these 
are all that I have seen from that formation. ‘They show a perfectly smooth and glossy 
surface, but the terminal portion is not perfect. Rubbed and worn specimens of a ribless 
Dentalium axe occasionally found in the Red Crag, but they are not perfect enough for 
determination. 
I have referred my shell as above, conceiving it most probably to be the same as the 
Mediterranean species. D. tarentinum, D. abyssorum, and the present species so much 
resemble each other that it is difficult to point out a sufficient difference for specific 
separation in the recent and perfect shells; while in the fossil it is even more difficult. 
Dentalium entale is given as a fossil of Kelsea Hill in the list of shells by Mr. 
Jeffreys, in Mr. Prestwich’s paper, ‘ Geol. Journ.,’ vol. xvii, p. 449. 
