XV111 



lave, 3 (b). 

 Imperforatum, 4. 

 Clausum, 4. 

 Glabrum, 4, f. 5. 



Gadus, 5,/. 62. 

 Trachea, 5,/. 61. 

 Subulatum(c),f. 60 



(6) The British Dentalia are peculiarly obscure, few 

 eabinets possessing more than one or two of the larger 

 species. I believe the chief difference of the Lyeve from 

 the Entalis, consists in its being snowy white, highly 

 polished (like enamel), and perfectly free from those ex- 

 tremely minute longitudinal striulae, 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, arid the Entalis in 

 the south. 



(c) 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 Deahayes' Monograph. The 



