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Some of the Lamarckian j^mpullaricE are viviparous, but I have it not 

 in my ponrer at present to ascertain vi^hich species ; the circumstances, 

 however, which I am about to mention seem to prove that one of these 

 viviparous species (if there be more than one) is sometimes reverse. I 

 had once a parcel of Ampul larise in a small tray, which I had packed 

 up in a box, and being subjected to rather violent shaking during a short 

 Journey, when the package was opened there were found in the tray 

 about twenty very young, but fully formed Ampullarise, two of which 

 were reverse. Now as there was not a single reverse AmpuUaria among 

 the old shells that were packed in the tray, these two reverse young ones 

 must have been the produce of one that was not reverse and most 

 probably belonged to the same brood as the other young ones. This 

 must have been one of those species of Ampullarise (hitherto so called 

 which have an horny operculum, for all the young ones are furnished 

 with such an operculum ; I would however suggest the propriety of 

 separating those with a shelly from those which have only an horny 

 operculum, if this has not already been done. 



A word on the subject of the British shell commonly called Nerita 

 littoreus and which Lamarck heis named Turbo neritoides, may not be 

 misplaced. The foot of its animal is divided by a longitudinal groove 

 in the same manner as that of Cyclostoma elegans. This fact was 

 pointed out to me by my friend Morris of Kensington, a few weeks ago 

 at Carnarvon. This shell does not belong to the true Neritae, and it is 

 improperly placed by Lamarck among the Turbines, it appears to be 

 more nearly related to the Jjittorinae ; though it is probable that upon a 

 more intimate acquaintance with it. Naturalists may think it necessary to 

 regard it as the type of a new genus. 



Helix Helmii, Gilb. This appears to me to be a very distinct species, 

 the shell is of a very pale horn colour, almost white, and extremely thin ; 

 its animal is of a dark blue grey colour, and it it remarkable that it is 

 always found nj)on the ground and not upon the surrounding vegetation. 



I have lately been requested by my friend Morris of Kensington to 

 compare some fossil Valvatae which he has found at Grays in Essex, with 



