:M0 Dr. Pfeiflfer's Observations on (he Family llelicidn-. 



ceedingly difficult group of the large extra-European forma* 



the teeth of the aperture and the folds of the columella are a 

 very uncertain character; sometimes they are present, some- 

 times missing : Pupa sulcata is perfectly toothless. On the 

 other hand, the great affinity of this group with Bulimus la- 

 btOSUS*, Br. is evident, and this can just as little be separated 

 from Bulimus /aba, Desh. {Partula australis, Fer.) as the latter 

 from Bui. cet/otis, Mke. (Auricula Sileni, Lam.) Bulimus ci- 

 trinus and the other true species of Bulimus (according to 

 Draparnaud !). Indeed the most certain proof of a genus 

 having been falsely established is when several of its spe- 

 cies are thrown from one to another ; or generally when we 

 are uncertain to which any species that occurs is to be car- 

 ried. 



From all these reasons I consider that the genus Pupa, Dr., 

 must be wholly discarded, and its species arranged with Bu- 

 limus. But the genus Clausilia, according to its old Drapar- 

 naudian characteristic, remains firm. Did there exist no other 

 distinctive character, the clausium — a part evidently ana- 

 logous to the operculum of several molluscous genera — would 

 alone suffice to establish the genus ; and if we define this with 

 Draparnaud' s short words thus : " Testa fusiformis ; peri- 

 stoma continuum oblongum ; clausilium !" we have a well-de- 

 fined whole. It is true, a portion of the species included 

 by Draparnaud in this genus, to suit which Lamarck (ed. 

 Desh. viii. p. 195.) says, Ce nom fut d'abord significatif ! 

 must then be excluded ; viz. 1°, all those which have no 

 continuous peristoma ; and 2°, those which have a circular 

 continuous peristoma but possess no clausium. Of the 

 former I will merely mention the Clausilia exesa, Spix 

 (Desh. No. 39.), and Turton's Balea fragilis, which indeed 

 is reckoned by Draparnaud, Nilsson, and Lamarck as a 

 Pupa ; but by Studer, C. Pfeiffer (vol. iii.), and Menke as a 

 Clausilia. Both must range, together with the genus Pupa, 

 under Bulimus. To the second section belong Lamarck's 



* Desh. No. 130. This beautiful species, adopted by Deshayes only from 

 Muller's excellent description, is in my possession. It is represented with 

 perfect truth in Chemnitz (ix. p. 1234.), but the figure in Gualtieri (T. 4. 

 R.) cited with a query has no relation to it, but belongs to the species which 

 Blainville (Malacol. tab. 39. fig. 5 a.) has figured as Pupa Mumia. 



