GASTEROPODA. 309 



Michaud, with which I have been presented by this most liberal author, 

 differ only from Mr. Alder's P. spirorbis in having a white rim within 

 the mouth : on this subject see Supplement to Mr. Alder's Paper in the 

 Newcastle Transactions, and Mr. Gray's edition of Turton's Manual, p. 

 267 ; in this work P. leucustoma, Mich., is referred to F. vortex, but if 

 this is to be considered distinct from P. spirorbis, to the latter P. leucos- 

 toma must be referred. 



P. nitidus, ]\Iull. 



Although somewhat rare, this species is distributed over Ireland. On 

 some living specimens taken near Belfast in Dec, 1834, by ]Slrs. Hincks, 

 and kindly sent to me, the following note was made — " tentacula moder- 

 ate, or rather short and uniform in colour with the body of the animal, 

 which changes with age, the adult (with shell 2^ lines in diameter) being 

 black ; younger individuals pale grey ; the shells of the latter are much 

 the more transparent.'' These animals seemed indifferent which side of 

 the shell was uppermost, and when undisturbed often moved along with 

 what is termed the under side next the surface of the water. 



P. contoiftts, Mull. 



Like the P. albiis, generally distributed over Ireland, but of more fre- 

 quent occui-rence, and in greater quantity where found than that species. 



P. lacustris, Lightfoot. 

 Cahir, County Tipperary, Mr. Humphreys. 



Sect. II. OPEKCULATA. 



Family Cyclostomid^e. 

 Gemis Cyclostoma. 



C. elegans. Lam. 



Dr. J. L. Drummond informs me, that when at Sandymount, near Dub- 

 lin, in 1816, in company with Mr. Tardy, a well-known entomologist, he 

 found one of these shells. In Dr. R. Ball's collection are specimens 

 which were obtained in Glasnevin Botanic Garden, Dublin, but here they 

 might have been introduced with plants from England ; in the cabinet of 

 Mr. O'Kelly of that city are two specimens found by himself at Portmar- 

 nock ; by Mr. S. Wright of Cork I was shown a similar number, said to 

 have been procured at Youghal. Notwithstanding this, I am not alto- 

 gether satisfied that the C. efer/ans is an indigenous species ; it has on 

 different occasions been introduced to the country in the present century, 

 but whether to any of the places mentioned previous to the specimens 

 being found there I am uninformed — the fact of only one or two indivi- 

 duals occurring anywhere looks suspicious. 



Dr. Turton states that he found a single shell of the Ci/dosfoma produc- 

 tum near the sea-coast in the West of Ireland. — Sfatiua/, p. 94. 



Several specimens of this shell were found by INIrs. Hancock on the 

 strand at Mullaghmore, near Bundoran, County Donegal. 



