19^1. KCNNARD & Woodward. — No)i-3Ia>i?ie Mollusca. 49 

 " From Shores of Lough Erne," Fermanagh. 



Vitrea crystallina (Miill.). Helix nemoralis, Linn. 



radiatula (Aid.). Cochlicopa lubrica (Miill.). 



Zonitoides nilidiis (Miill.). Jaminia cylindracea (Da Costa.). 



Euconulus julvns (Miill). Claiisilia bidentata (Strom.). 



Pyinmidula yotundata (Miill.). Succinea elegans, Risso. 



NOTES ON THE SPECIES. 



Limnaea stagnalis (Linn.). — The examples of this species from Lower 

 Lough Erne are interesting and differ markedly from the type, and would 

 be termed L. Contagnei, Loc. by French authors, but in our opinion it is 

 only a mutation caused by environment. Several of the shells are 

 noteworthy in possessing a change of colour on the last whorl. The 

 shell is normal in colour except for a band about 12 mm. wide which 

 extends right across the body whorl. Here there are numerous white 

 lines parallel with the suture, and this band is succeeded by shell of the 

 normal colour, thus clearly showing that it is not a mere individual 

 mutation, but arises from some extraneous cause which only acted for a 

 limited period. 



Limnsea pereger (Miill.). — There is not much variation in the examples 

 of this species except, perhaps, in the height of the spire. One or two 

 specimens from Lower Lough Erne approached the form from Lough 

 Neagh which is usually called var. lacustris. Leach (an anatomical 

 exammation of the Lough Neagh shells is greatly to be desired). All 

 the examples are small, the largest measuring 17 by 13 mm. There is 

 a total absence of inflated forms. 



Limnsea pratenuis, Bowell. — It is a matter of congratulation that 

 through the labours of Major Trevelyan we have been able to examine 

 several series of this species. Originally described from Lough Nagarriva, 

 South Kerry, we can now add L. Acapple, L. Derg, and L. Vearty, 

 examples from these three lakes having been examined anatomically by 

 Mr. Bowell, and on conchological grounds we have referred the shells 

 from L. Tullynasiddagh to this species. It is extremely probable that 

 it has a wide range in Ireland, and judging from material in the British 

 Museum (Natural History) it, or a closely allied species, occurs in the 

 Faroes. The species varies somewhat in the height of the spire, those 

 .- from the original locality possessing a very short spire, whilst the 

 examples from L. Acapple and a few from L. Vearty have this character 

 more pronounced. It would appear from the L. Vearty specimens that 

 there is some variation in the inflation of the last whorl, for in some of 

 these examples the last whorl is inflated and the spire is quite hidden, 

 the shell resembling a Bulla and being markedly different from any other 

 form of European Limnaea we are acquainted with. 



Limnaea palustris (Miill.). — The examples of this species, whether (rem 

 Lower Lough Erne or the smaller lakes, all present the same facies. 

 They are decidedly small, some are much eroded and slightly decollated 

 and represent the form called bv French authors L. jusca, Pfr. 



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