GASTEROPODA. 93 
DrnTALIuM aByssorum, Sars. Crag. Moll., vol. i, p. 189, Tab. 20, fig. 2 (as D. entale). 
Locality. Upper Glacial, Bridlington. 
The shell figured and described by me from Bridlington appears to belong to the 
arctic and deep water species or variety, abyssorum. 
Dentanium prEnrauis, Zinn. Crag Moll., vol. i, p. 188, Tab. XX, fig. 1 (as 
D. costatum). 
DenTaLiuM costatum, J. Sow. Min. Con., t. 70, fig. 8, 1814. 
Localities. Cor. Crag, Sutton, and near Orford. Red Crag, Sutton. Middle 
Glacial, Billockby. 
In the ‘Crag Moll.’ (vol. i, p. 189) I mentioned that I thought this Crag shell the 
same as the living Mediterranean shell, D. dentalis, Linn., and as this seems now the 
general opinion, I have here placed it under Linné’s name. ‘Two imperfect specimens, 
showing the strong coste, but flattened by wear, have occurred in the Middle Glacial of 
Billockby, and I have no doubt of their belonging to this species. 
Actmon nox, J. Sow. Crag Moll., vol. i, p. 169, Tab. XIX, fig. 6. 
Localities. Red Crag, Walton, Brightwell, Newbourn, Butley. Fluvio-marine 
Crag near Norwich ? 
This shell is given by S. Woodward, in his ‘ Geology of Norfolk’ (1833), as occurring 
rarely near Norwich, but his son Dr. Woodward, in his list in ‘ White’s Directory,’ treats this 
as a mistake for Acteon (Tornatella) tornatilis, which also occurs in the Fluvio-marine Crag 
of Bramerton. I however find that Acton Noe was among a set of shells from Norwich 
submitted to me and the late G. B. Sowerby by Sir Chas. Lyell, and published at p. 328 
of vol. III of the ‘ Mag. of Nat. Hist.,’ New Series, which were by us carefully compared 
and considered. Therefore, although I have not since met with the shell from the 
Fluvio-marine Crag, I give it from that Crag with a doubt. Mr. Jeffreys has stated, 
‘Quart. Journ. Geol. Sci.,’ vol. xxvi, p. 288, that this shell has been found fossil in 
Iceland by Prof. Steenstrup. Dr. O. Mérch also gives this species in his list of Crag 
Shells ¢ Geol. Mag.,’ vol. viii, p. 395), from Hallbjarnastadir, in Iceland. 
ACTON TORNATILIS, Linn. Crag Moll., vol. i, p. 170, Tab. XIX, fig. 5. 
Localities. Cor. Crag, Sutton. Red Crag, Sutton and Butley. Fluvio-marine Crag, 
Bramerton. Chillesford bed, Burgh and Aldeby. 
