of Great Britain. 115 



of England, frequently within tide- way. It never grows to half the 

 usual size of the species found in ponds, and is intermediate between 

 that and the following. 



3. Minutus, Drap. 



A variety of this, much smaller in size, is also found on the mar- 

 gins of rivers. It is the var. y. of Draparnaud, concerning which 

 he says, " J'ignore si ce n'est pas une espece distincte." The small 

 variety is also found in mountain streams. A careful examination 

 of this genus may enable malacologists to discover more definite cha- 

 racters to distinguish this species than those already employed. 



4. Elongatus, Drap. 



5. Pereger, Drap. 



Var. 1. L. ovatus, Drap. 



2. L. lineatus. Bean. 



3. Helix lutea, Mont. 



4. Gulnaria lacustris, Leach. 



6. Acufns, JefF. 



This species is intermediate between L. pereger and L. auricu- 

 larius, and, if not distinct, may, Mr Jeffreys observes, lead us to 

 unite them all into one. It comes very near L. lineatus. Bean. 



7. Auricular ins, Linn., Drap. 



8. Involutus, Thompson, MS. 



Mr Thompson of Belfast announced the discovery of this beauti- 

 ful new species to the Linnaean Society in J 834, and we shall no 

 doubt be gratified with a description of it in his promised catalogue 

 of Irish land and fresh water Mollusca. It would be interesting to 

 know if the animal corresponds with that of L. glutinosus, as this 

 circumstance, taken in conjunction with the shape of the shell, would 

 go far to establish Nilsson's genus Amphipeplea. 



9. Glutinosus, Mull., Drap. 



Amphipeplea glutinosa. Nils. 



Concerning L. detritus, which has so long appeared on our lists, 

 I can add nothing to what has already been said by Dr Turton and 

 Mr Jeffreys. Since the former gentleman withdrew his vStatement 

 of having found this species in Ireland, Mr Bryer remains our only 

 authority for considering it as British ; but whatever the original 

 shell found by Mr Bryer may have been, the specimens now in Eng- 

 lish cabinets appear all to belong to the genus Bulimus, and are 

 most likely foreign. Captain Blomer sent me a foreign Paludina 

 for this shell a few years ago. 



The genus Auricula has not been included in this catalogue, 

 though one of the species, A. denticulata, may be considered to be 

 more fluviatile than marine. I found this species last summer on 



