250 Mr. J. Gwyn Jeffreys on Dredging 
proposed for the reception of a small Sicilian fossil—his Denta-. 
lium ovulum) the shell is not cylindro-conical as in Siphono- 
dentalium, but is tumid in the middle or anterior portion, some- 
times awl-shaped; and the mouth is encircled by a narrow rim. 
In Cadulus the shell is quite smooth, transparent, and lustrous; 
in Siphonodentalium it is striated or exhibits the lines of growth, 
and is semitransparent. The long-lost Dentalium gadus of 
Montagu, an allied species (D. clavatum of Gould) from the 
China Sea, another species which I observed in the late Mr. 
Cuming’s collection, from Mindanao (erroneously named D. 
acuminatum, Deshayes), and D. coarctatum of Lamarck (a ter- 
tiary fossil) apparently belong to Cadulus, and certainly not to 
Ditrupa (properly Ditrypa)—a genus of testaceous Annelids the 
shell of which is different in structure and composition from 
that of Cadulus or of Siphonodentalium (the mouth is contracted 
or pinched-in), and the animal is annulose and has a circular 
operculum. On the other hand, several kinds of shelly cases 
described as Dentalia really belong to Ditrypa. If Cadulus is not 
generically distinct from Stphonodentalium, the former of these 
names has priority ; and we shall thus be able to expunge a more 
than sesquipedalian name from the terminology of the Mollusca. 
The diagram now exhibited is an enlarged representation of the 
figures of S. Lofotense and S. subfusiformis, in an admirable 
paper by Professor Sars, published in the Transactions of the 
Academy of Sciences at Christiania for 1864; and it will serve 
to explain the nature of these extraordinary mollusks. One of 
our species is 
Siphonodentalium Lofotense, Sars 
(“ Malacozoologische Jagttagelser,” in Vid.-Selsk. Forh. 1864, 
p- 17, figs. 29-33), ranging from the Loffoden Isles to Chris- 
tianiafiord, at depths of between 30 and 120 fathoms. It was 
rather plentiful among sandy mud in St. Magnus Bay, at the 
depth of from 60 to 80 fathoms; and I had found it in 1846 
when dredging off Skye, in 1864 off Unst, and last year in the 
Minch. The shell may easily be passed over (as it was by 
me) for the young of Dentalium entalis; hut it is more curved 
and cylindrical, the mouth and corresponding lines of growth 
slope backwards, and the margin of the posterior orifice is regu- 
larly jagged (having two slight notches on each side), and this 
extremity does not form a bulbous point in the fry. One of 
the characters given by Sars (“‘margine aperture posterioris 
integro”’) should be amended. My observation of the animal 
agreed with his, except that the foot is vermiform and has a 
fine point, the disk being expanded and assuming the shape of 
a flower only when the Stphonodentalium wishes to obtain a 
fulcrum and keep its place in the sand. The foot of Nucula 
