130 Proceedings of the Royal Irish Academy. 



P. glaber Jeff. — North Kerry and Mid Cork, doubtful : no specimens in 

 existence. 



Segmentina nitida Miill. — Reported from Co. Tipperary by Jeffreys and 

 others. Probably owing to misinterpretation oi Planorhis niiidus, Thompson, 

 which is of course P. fontanus Lightfoot. 



Acicula lineata Drap. — Queen's County, doubtful : recorded in the diaiy 

 of the late Eev. B. J. Clarke from Spire Hill. 



Paludestrina ventrosa Mont. — A smgle dead example of this shell was 

 taken some years ago by Mr. J. N. Milne at Trawbreaga Bay in East Donegal. 

 This must be taken as a doubtful record until liviag specimens are foimd. 



Paludina vivipara L. — The record of Captain Brown seems so emphatic 

 that it is impossible to consider it erroneous, and there is a possibility that 

 the species may have at that time lived in one of the several mill-dams at 

 Newtownards. Although Brown states that he found it " in a stream," this 

 is not likely, as the only one near Newtownards is swift, stony, and shallow, 

 and very different from the usual habitats of this shell. The finding of a dead 

 specimen near Limerick by Mr. Fogerty [86] has awakened fresh interest in 

 this species ; and I have often wondered lately if it were possible that Captain 

 Brown had collected his specimens while stationed somewhere in the centre 

 of Ireland, and afterwards forgotten and mistaken the locality. There are 

 many unworked areas in the central plain ; and there seems no reason, from 

 its distribution in Britain, why P. vivipara should be absent from Ireland. 



Neritina fluviatilis L.— East Cork, doubtful. 



Dreissensia polymorpha Pallas. — Reported from Dublin liy Lowe [146] in 

 1883. Undoubtedly an error. 



Sphaerium rivicola Leach. — Reported from the Liffey at Lucau, Dublin, 

 undoubtedly a mistake. Some collector in all probability mistook some of the 

 very large shells of Pisidiion- amnicum., which are to be found in this river, for 

 the present species. (See Forbes and Hanley, ii, 135.) 



Pisidium henslowanum Shepp. — Recorded from the River Dodder, in Dublin, 

 by Clarke in his diary. Doubtful. 



P. subtruncatum Malm. — North and South Kerry, West and East Cork, 

 Waterford, Limerick, Kilkenny, Wexford, Queen's County, West Galway, 

 Wicklow, Dublin, Longford, Leitrim, Louth, Tyrone, Armagh, and Derry. 

 Doubtful. 



P. pulchellum Jenyns.— Mid and East Cork, Kilkenny, North-east Galway, 

 Dublin, and Louth. Doubtful. 



P. casertanum Poll. — North Kerry, East Cork, West Galway, Dublin, 

 Cavau, Monaghan, and Armagh. Doubtful. 



P. obtusale Pfeiffer. — West, Mid. and East Cork, Waterford, Kilkenny, 



