76 MR. J. COSMO M:5.x.viLL ON 



V. Notes on the Subgenus Cylinder {Mom^fort) of Conus. 

 By J. Cosmo Melvill, M.A., F.L.S". 



Eead before the Microscopical and Natural-History Section, 

 February i6, 1885. 



Few genera stand out more naturally and prominently in ; 

 the animal kingdom than the large assemblage of Mollusca 

 associated under the name of Conus (L.). Few fall so 

 naturally into subdivisions and^ as a rule^ present such 

 well-marked specific differences. Recognized as they all 

 are at a glance by the inversely conical shell, with length- 

 ened narrow aperture and simple inner lip, they are, with 

 but one exception, natives of tropical or subtropical seas, 

 the exception being a not uncommon S. Mediterranean 

 shell (C mediterraneus, L.). They approach in form, 

 through C. Orbigmji and others of the section Leptoconus, 

 to the Pleurotomse, especially shells of the section Genota, 

 e. g. mitriformis and papalis ; and, on the other hand, 

 through C. mitratus, of the subgenus Hermes, to the 

 anomalous genus Dibaphus, and, through that, again, to 

 the Mitres. 



This is as regards the form only : for the mollusc itself 

 differs in some important particulars, and hence the Cones 

 are classed by themselves in the suborder Toxifera, of 

 Gasteropoda Pectinibranchiata, differing from the other 

 allied suborder Proboscidifera — to which the Pleurotomse 

 and Mitres, just alluded to, belong — by the proboscis being 

 furnished with a tube containing bundles of sharp, needle- 

 like, barbed teeth at the end, instead of the usual lingual 

 band, covered with short teeth. This tube, according to 

 Adams, is extended below, at right angles to the cavity. 



