In _Voluta_ and _Mitra_, the two typical groups of this family, the variations of form are so striking, and the species so numerous, that we readily assent to the plan, proposed by others, of further dividing them into genera: but in the aberrant group, containing _Oliva_, _Ancillaria_, and _Marginella_, the forms are less diversified, and the species fewer; the minor divisions may therefore, for the present, be termed sub-genera. The approximation of _Marginella_ to _Voluta_ has frequently been stated. In M. _bullata_ we have a miniature melon Volute, while M. _faba_ is a no less obvious representation of V. _magnifica_. Hence these forms appear typical. Yet M. _persicula_ and _lineata_ cannot well be placed with either, as their characters seem to indicate a direct analogy to _Conohelix_ among the Mitres. As to _Volvaria_, we concur with other writers, in thinking that the French Conchologists have erroniously blended that genus with _Marginella_. ---- MARGINELLA guttata. _Oval, spire concealed, covered with transverse oval spots margined with white, somewhat ocellate, and disposed longitudinally; pillar 4 plaited._ ---- We could give no correct idea of this very pretty shell, without enlarging the figures; the natural size is indicated by the horizontal line. Our specimen is the only one we have yet seen, nor do we know its habitat. * * * * * * [Illustration: MARIUS _Cinna_] MARIUS Cinna. ---- Family Nymphalidæ. (Stirps. 3? Horsf.) GENERIC CHARACTER. Larva and pupa _unknown_. Perfect insect. _Wings_ Papilioniform, caudal appendages long, acute. _Palpi_ porrect, approximating, and meeting at their tips so as to form an acute cone: the whole covered with compact scales. Anterior feet small, slender, imperfect, the tarsal joints? concealed by long hairs: club of the antennæ terminal, sub-fuciform and cylindric. Body short, thick, robust. Type, _Papilio Marius_. Auct. ---- SPECIFIC CHARACTER. _Wings above brown, with two unequal white bands; beneath white, with narrow fulvous bands; basal angle of the posterior wings with an orange spot, ocellated with black._ Papilio Cinna. _Cramer Vol. I. pl. 100. f. 8._ ---- Cramer describes this elegant Butterfly as a native of Surinam, and our own specimens were received from the same country. All the species of this group that have yet fallen under our inspection, are natives of South America. Their flight is high, powerful and rapid: the predominating colour on the upper surface of their wings is brown, and on the under white.