XVill 
Leve, 3 (6). | Gadus, 5, f. 62. 
Imperforatum, 4. Trachea, 5, f. 61. 
Clausum, 4. Subulatum (c),f. 60 
Glabrum, 4, f. 5. | 
LLILIPLILI PDD ADD DD 
LPLDLLDIDLI ILS. 
(4) The British Dentalia are peculiarly obscure, few 
cabinets possessing more than one or two of the larger 
species. I believe the chief difference of the Lave from 
the Entalis, consists in its being snowy white, highly 
polished (like enamel), and perfectly free from those ex- 
tremely minute longitudinal striule, which in perfect spe- 
cimens will be always found, under the lens, in that 
species. It is also more attenuated and longer, but this 
latter character is of little avail for comparison, as this 
genus is rarely found alive and perfect. This species is 
chiefly found in the north of England, and the Entalis in 
the south. | 
(ec) Subcylindrical, elongated, polished, pale horn 
coloured, perfectly smooth, moderately arcuated. Larger 
aperture contracted, perfectly round, smaller extremity 
with a minute round perforation, no fissure. Length one 
inch, breadth at the broadest part nearly a line, at the 
smaller end, one third of a line. This is the Ditrupa 
Subulata of Berkely in the Zoological Journal, and the 
Dentalium Subulatum of Deshayes’ Monograph. The 
