GASTEllOPODA. 303 



Genus Aukicula. 



A. denticalata, Mont. (sp.). 



Bangor, Miss A. M'Adam ; 

 Youghal, :Miss M. Ball ; 

 Portmarnock, j\Ir. Warren. 



A. hidentata, Mont. (sp.). 

 General along the coasts of Ireland. 



A.fusiformis, Turt. (sp.)- 

 Mr. Alder, on examination of a shell from Portmarnock, in Mr. War- 

 ' ren's collection, agreeing with the description of Voluta fnsiformis, was 

 disposed to believe it worthy of specific rank : a similar sliell was obtain- 

 ed at Bundoran by Mrs. Hancock. 



Family LiMN.EAD.E. 



Genus LiMXEUS. 

 L. auricularius, Drap. 



Thi'ough deference to those who have paid much more attention to the 

 subject than myself, I note this Limneus under the head of a distinct spe- 

 cies, although I am disposed to believe that it is only an extreme form of 

 L. iwreaer. The L. auricularius, as figured in both editions of Turton's 

 Manual, and by Draparnaud, is not very unfrequent in Ireland, but of 

 the extremely expanded form rejjresented by Rossmassler is very rare, 

 and from one or two still ponds only, abounding in subac^uatic plants of 

 various species, have I seen it. Pfeiffei''s figure (part i. t. 4. f. 17, IS) 

 is somewhat intermediate between those just mentioned, and correspond- 

 ing to it I have procured specimens. All forms, from the ordinary L. 

 pereger to the L. auricularius, it seems to me, may be closely traced blend- 

 ing into each other — reference to the figures in many works will be found 

 to present various forms, though in all the aperture is greatly expand- 

 ed. Some specimens of L. auricularius, which I collected in Stow Pool, 

 Lichfield, in July, 1836, are more distinct than any Avhich I have seen 

 represented ; the spire is more minute, and the up])er part of the outer 

 lip goes off" from the body of the shell in the form of a straight line ; 

 but of all the individuals obtained on this occasion no two are pre- 

 cisely alike, but vary from the extreme form described to the L. ovatus, 

 Drap. 



L. perecjer, Drap. 



This species, presenting endless variety, is abundant throughout the 

 waters of Ireland, from the smallest cbain to the vast expanse of I>ough 

 Neagh. Some of the forms which have been considered as distinct spe- 

 cies may be enumerated as occurring in this country, as L. oratus, Drap., 

 X. intermedia, Michaud (Comp. pi. 16, f. 17, IS), L. marf/inata, Mich. 

 (Id. f. 1<5, 16), L. lincatus. Bean, L. acutus, Jcff'reys — of these two last I 

 judge from comparison of authentic s])ccimens, the former favoured me 

 by Mr. Alder, the latter by their describer. One variety seems to require 

 especial notice — the Gulnaria lacustris, Leach. On the shores of Louglis 

 Neagh and Erne I liave collected specimens identical with those so named 

 by Dr. Leach in the British Museum, and which are from the lakes of 



