PL AN AX IS. 



Zam^ Hist. Nat. des Anim. sans vert. VII. p. 50. 



^ESTA ovato-conica, solida. Apertura ovata^ 

 sublongitudinalis. Columella basi depressa ob- 

 lique truncata, sinu perangusto a labro separata. 

 Labrum facie interna sulcata, aut lineata, et 

 infra marginem superiorem callo decurrente 

 distinctum. Operculum tenue, corneum. 



Planaxis is ^ genus of shells lately detached by Lamarck 

 from the Buccinum of all authors; he says^ they are 

 marine shells^ related to the PhasianellcB, but distinguished 

 by their columella being truncated at its base^ as in Mela-^ 

 nopsis. ITie callosity running under the summit of their 

 right lip seems to bring them near to the Buccina and the 

 PurpurcE," and, indeed, we may venture to give it as our 

 opinion that the Planaxes are much more nearly related 

 to the Buccina than to the Phasianellce. 



They are ovately conical, thickish shells, whose aper- 

 ture is rather longer than it is wide; base of the columella 

 depressed and obliquely truncated, and divided from the 

 buter lip by a very narrow canal. The inside of the outer 

 lip is transversely grooved or plaited, and there is a pro- 

 minent callosity running under the summit of the right 

 lip. The operculum, which Lamarck had not seen, but 

 which we have had an opportunity of observing in one 

 species, is thin and horny. 



We know but few species of Planaxes, which are all 

 small and generally transversely striated or grooved on 

 the outside, sometimes smooth, and covered with a light 



