450 Ml". W. Clark un the Cuuovulidffi, 



the readers of the ' Annals.' These species have run the gauntlet 

 through nearly the entire range of the British Gasteropodous 

 molluscan genera in search of a resting-place ; it is needless to 

 allude to these ancient and variable depositaries ; I will therefore 

 only mention the recent genera in which they appear to have 

 obtained that sort of improved provisional settlement^ which is 

 usually the precursor, from the many malacological facts that 

 have been obtained, of a definitive natural position. 



The more recent receptacles of these interesting objects are, 

 Mr. Lowe's genus Parthenia, Doctor Fleming's Odostomia, 

 M. Philippi's Chemnitzia, and the Truncatella and Ealima of 

 Risso, with M. Loven's Turbinella and Aclis. The admirable 

 manner in which Mr, Lowe has described the animal and illus- 

 trated his Parthenia, causes much regret that we must concur 

 with M. Philippi in not using this appellation in consequence of 

 the pre-occupation of the term. Though we believe Dr. Fleming's 

 genus Odostomia has the priority of time, yet from the variable- 

 ness and instability of the principal conchological character, the 

 fold on the pillar, it cannot be maintained either generically or 

 as a group : for instance, the Odostomia interstincta has often the 

 fold, and often is without it ; the O. indistincta never has a tooth ; 

 the O, excavata is sometimes with and sometimes without it. 

 ]\Iany of the more elongated and turreted species are without a 

 fold ; nevertheless in some, for instance the O. acicula, the tooth 

 is present, and often wanting, as our cabinet will show ; therefore 

 the appellation of Odostomia to this tribe is incongruous and a 

 complete misnomer. The term cannot even be admitted as a sec- 

 tional arrangement, as it would separate individuals of the same 

 species, for example, the toothed interstincta and the edenticular 

 one ; on these accounts we are reluctantly obliged to decline the 

 use of the term. Besides, we believe that this fold or tooth has 

 had attributed to it far more generic value than it deserves : it 

 probably gives some support to the body as o. point d'appui; but 

 the malacology of the animal, whether with or without it, affords 

 no corresponding variation. We therefore propose to adopt 

 M, D'Orbigny's genus Chemnitzia for those species with or with- 

 out a tooth, smooth or plicated, many or few volutions, which 

 have as a component of their specific characters a moderately 

 long proboscis, not an internal one, which can be withdrawn or 

 hidden under, and again evolved from the tentacular veil. All 

 these species cannot be mistaken, as whatever may be the spe- 

 cialties of the animals, they have the apical one or two turns, re- 

 flected on the following descending one : this is a constant cha- 

 racter ; I have never met with a departure from it. 



The next genus of this family is Eulima, which, though closely 

 allied to Chemnitzia, is nevertheless distinct in various points to 



