GALEOMMA. 185 



and, moreover, it wants the characteristic feature of the 

 last-mentioned genus, viz. the numerous cardinal teeth : 

 the hinge of Galeomma has no tooth of any kind. Its 

 habit of active locomotion, the structure of its shell, and 

 its internal cartilage connect it with Lepton; but in 

 that genus the shell is capable of being completely 

 closed, and it is furnished with both cardinal and lateral 

 teeth. Forbes and Hanley united the present family 

 with KelliidcB ; and Clark placed it, as well as the genus 

 Lepton, in the Area family. Gray proposed to make 

 one family of Galeomma, and another of Lepton; but 

 the latter does not form an isolated or aberrant group, 

 like the former ; and if every genus is to be raised to 

 the rank of a family, the organization of natural history 

 may be compared to an army consisting of officers only. 

 The members of this family, although by no means 

 numerous, are widely distributed over the globe, except 

 towards the north pole. Our single European species 

 does not seem to have travelled to a higher latitude than 

 the southern coasts of Great Britain. 



Genus GALEOM'MA*, Turton. PL IV. f. 6. 



Characters described above, as belonging to the 

 family. 



The singular shell which represents this genus in the 

 European fauna was discovered by Dr. Turton nearly 

 forty years ago ; and its no less remarkable animal was 

 first noticed by Scacchi, a Neapolitan conchologist. 

 In 1834 Quoy and Gaimard published an account of 

 another species, which they referred provisionally to 

 Psammobia, and which constitutes one of the numerous 

 additions to science made in the course of their cele- 

 * Cat's eye. 



