CONCHOLOGY. 



in preference to other systems, that proposed by Lamarck. 

 It will have been perceived that our observations, so far, have been 

 confined chiefly to that conspicuous shell described by Linnaeus 

 under the name of Bulla Achatina, and that the most we have 

 ventured to advance respecting the shell which constitutes the subject 

 of the present plate, has been to intimate that it appeared analogous 

 to the Bulla Achatina ; we shall now be more explicit, it is either a 

 species immediately approximating to that shell, or a variety 

 possessing a peculiarity in the formation of the aperture or opening 

 of the mouth, not usually observable in that species, namely, the 

 reflected margin of the lip, and that in this respect it is at variance 

 with the characters assigned by every author to the Bulla Achatina 

 of Linnaeus, under whatever name they have described or men- 

 tioned* it. 



Lamarck in establishing his genus Achatina, the genus to which 

 this shell approaches nearer than to any other, thus defines its 

 essential character : " Shell ovate or oblong, aperture entire, longi- 

 tudinally longer than broad : lip acute, and not reflected ; pillar 

 smooth and truncated at the base." But, in the shell we are con- 

 sidering, the lip is distinctly marginate, and reflected or turned back, 

 notwithstanding which, its near affinity to the Achatina tribe of 

 Lamarck, has induced some collectors to name it as a new species, 

 Achatina Marginata, the Marginate Achatina. But, how is this, it 

 may be demanded, to be reconciled with the express character laid 

 down by Lamarck himself, "labro acuto nunguam reflexo" or as 

 repeated again in the language of his country, " abord droit tranchant 

 jamais reflechi and it will really appear upon inspection of the 

 lip of the shell Bulla Achatina, that it is perfectly acute at the edge, 



VOL. V. D 



