AMPULLARIA 



Lam, — Syst. des Anim. sans vert. p. 93. 



■-^ ^ ^ 



Testa globosa^ aut globoso-discoidea aut disco- 

 idea umbilicata ; spivd brevi ; anfractibus ven- 

 tricosis : aperturd oblonga^ integra altitudine 

 latitiidinem superante ; Operculo testaceo^ annu- 

 laris nucleo subcentrali^ laterali. 



In introducing the Genus AmpuUaria to the notice of our 

 readers, we feel ourselves called upon to explain the cha- 

 racter which Lamarck gives to its animal inhabitant, of 

 being furnished with an horny operculum, for we believe 

 that all the Ampullarice possess an operculum as completely 

 shelly as the shell itself, and covered with precisely the 

 same kind of epidermis. AVe do this with regret, because 

 we never intended to arrogate to ourselves the character of 

 conchological censors, and because in the prosecution of 

 our work we find so many errors, and so general a care- 

 lessness in description as well as nomenclature ; but we 

 hope to do it with tenderness, feeling our own liability to 

 error, and not doubting that in many instances we shall be 

 obliged to claim the same degree of indulgence we would 

 extend to others. We suppose then, that Lamarck, \vhen 

 he first established the Genus, meant to include in it not 

 only the nearly globose, umbilicated shells, now distin- 

 guished by the name of AmpuUaria^ but also some others 

 which he has since called Paludince^ and which have truly 

 an horny operculum and are more turrited shells. We are 

 convinced also, that there exists a much more considerable 

 difference between the true A?npullaria3 and the Planorbis, 

 than appears from the consideration of the characters 

 Lamarck has assigned to them in his Si/steme^ which he 

 there make© to consist almost entirely in the discoid form 



