Genus Latirus. 365 



An Historical Account of the genus Latirus (Montfort) 

 and its dependencies, with descriptions of Eleven 

 new species, and a Catalogue of Latirus and 

 Peristernia. By James Cosmo Melvil, M.A., F.L.S. 



(Received March 24.thy i8gi.) 



(I.) Early History and Classification. — When Linnaeus 

 first drew distinctions between the various marine Gastero- 

 pods, and assigned them to families and genera, he, and his 

 immediate successors, until, indeed, the time of Cuvier and 

 Lamarck, relied entirely upon the form of the shell alone, 

 and usually took some one prevailing characteristic, such as 

 a straight prolonged canal for instance, or a rounded mouth, 

 however different in other respects the shells were from 

 each other, dismissing their inhabitants in one terse sentence, 

 " Animal a Limax" Manifestly, by this rule, certain ranges 

 of molluscs, the salient characters of which were not dis- 

 cernible without considerable study, especially of the animal, 

 fell together into a heterogeneous " olla podrida," from which 

 it has taken much time and patience for subsequent authors 

 to extricate them. 



Accordingly, it is not surprising to find, under the 

 Linnean system, the few types then known of the genera 

 we are about to discuss found in Miirex (L.), in company 

 with what are now considered Murex proper, Ranella, Triton, 

 Purpura (pars), Phos^ Struthiolaria^ Pleurotoma, Fusus, 

 Neptunea, Pyrula, Ficulidce, Hemifusus, Mangilia, and 

 Cerithidce. They are placed in the ninth of the twelve 

 divisions by the late writers on the Linnean system {e.g., 

 Mawe, 1823), in which the subdivision into two families is 

 recommended, the first, consisting of shells turreted, outer 

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