448 



CONIDtE. 



To a person unacquainted with exotic, and at the same 

 time unversed in fossil Conchology, the association of the 

 ftisiform shells, often called PleurotomeE, with Conus, will 

 appear unnatural. There is really a very complete passage 

 between them and the true Cones, although the extremes 

 of each have little besides the possession of a spire, and 

 the canaliculated aperture in common. The animals are, 

 however, very similar. In outward conformation thej"^ 

 resemble those of the Mtiricida, but their dentition, as 

 first shown by Loven, is of an entirely different type. 

 The presence or absence of an operculum in this tribe is 

 so variable a character, that it might almost be termed 

 capricious. The genus Conns, after which the group is 

 designated, is a vast and beautiful assemblage of brilliantly 

 coloured Mollusks, almost all now confined to the tropics, 

 though during more ancient times several Cones inhabited 

 the Britsih area. 



MANGELIA. Leach. 



Shell turriculate, fusiform, variously sculptured with 

 spiral or longitudinal ribs or strife, or both ; sometimes 

 smooth ; spire produced. Aperture, with the outer li2> 

 more or less sinuous and retiring at its junction with the 



