Stelfox — List of Land and Freshwater Mollusks of Ireland. 131 



West Galway, Meath, Sligo, Cavaii, Louth, West Donegal, Tyrone, Armagh, 

 and Derry. Doubtful. 



P. nitidum Jenyns. — East Cork, North Tipperary, Carlow, Queen's County, 

 Wicklow, Meath, Sligo, Cavan, and Louth. Doubtful. 



P. pusillum GmeUn. — North Kerry, Mid and East Cork, Waterford, 

 Kilkenny, West Galway, Kildare, Wicklow, Westmeath, Longford, East 

 Mayo, Sligo, Leitrim, Cavan, Louth, Tyrone, and Armagh. Doubtful. 



P. personatum Malm. — Cavan, Armagh, and Down. Doubtful. 



P. steenbuchi Moller. — Westmeath, doubtful. 



4. List of Introduced Species. 



We have two kinds of introductions to deal with — " natural " and 

 " artificial." The former includes those shells which from time to time may 

 be washed up on our coasts by the sea, or those brought by the many casual 

 methods which have been appealed to by naturalists and others to account for 

 the present geographical distribution of plants and animals. 



Unsuccessful Natural Infrocluctioiis. 



The only species of which I can find any record of natural introduction are 

 Pomatias {Cyclostoma) elegans and P. ferrugineus. Neither of these shells, 

 however, has been able to establish itself in Ireland, although they are both 

 better adapted to withstand immersion in the sea than the great majority of the 

 species found in this country. Even if able to reach our shores alive, it seems 

 probable that, under present conditions, "alien" species, unless specially 

 protected, would be speedily wiped out of existence by the competition of 

 the truly native fauna. 



Pomatias elegans Miill. — Sea-borne specimens of this opereulate ha^-e been 

 recorded from various places on our coast. Forbes and Hanley [94] mention 

 that as many as 100 specimens were washed up near Bundoran (East Donegal) 

 in one day. 



General Distrihution. — Widely distriljuted over Europe, and occurs in 

 Britain as far north as Lancashire and Yorkshire. 



P. ferrugineus Lam. — Tliis is the Cydostoma productum Turton, recorded 

 by Thompson as found by Dr. Turton near the sea in the west of Ireland. 



General Distrihution. According to Forbes and Hanley this shell is found 

 in Algeria, Balearic Isles, and soiithern Spain. 



Between the two groups — natural and artificial — I must place two species 

 whose origin is unknown. In the case of these, undoubted introductions, there 



[S2] 



