192 The Irish Naturalist. September, 



PlanorbiS contortus, L. — Tvakelets on Rosses Point; I^ough Gill ; 

 Gleucar (Sligo); River at Union Wood, Collooney; Glencar Lake 

 dredgings. 



P, albus, Mull. — In lakelet, Rosses Point ; very common dead on shores, 

 Lough Gill ; alive on Yellow Water-lily leaves in pools near Doonee 

 Rock ; pond, Carrowmore ; river at Collooney ; Glencar Lake (Sligo). 



P. crista, L. — Lough Gill, rare. One very large distorted specimen is 

 twice the size of any Irish specimen we have ever seen ; it measures 

 3x2 mm., the final whorls crossing the first at an angle of about 

 45% and detached in places. Owing to its size, this shell puzzled us 

 very much. Not common in lakelet, Rosses Point ; Cliffony, 1900 ; in 

 myriads in a small pond near Kilmacowen old church, with vars. 

 naiitileus and laevigata, 1900. These specimens are beautiful objects 

 under the microscope, as they are covered with masses of diatoms, 

 several species being represented. (See p. 214.) 



P. fontanus, Lightf — Moderately common on underside of leaves of 

 Water-lily {N. luteum) in pools on shore at Doonee Rock ; Glencar 

 (Sligo ?) T900. We took it also in the Bundrowse river, which 

 separates Leitrim and Donegal, in 1899. A very local species in Ire- 

 land, and rarely plentiful. 



Ancylus fluviatllis, Mull — Large and variable as to shape on margins 

 of Lough Gill ; many also dead in shell debris on shores of Glencar 

 Lake (Sligo). 



A. lacustrls, L. — Partly grown specimens under Water-lily leaves in 

 little pools on shore near Doonee Rock. 



Acme Ilneata, Drap. — Var. alba in moss and liverworts on side of path 

 in the glen, Lissadill, very large and fine ; both type and var. in wood 

 below Doonee Rock ; type and var. common in moss, Glencar (Sligo) ; 

 nice specimen of both in the moss Hypniim splendens on the talus 

 slopes in the Swiss Valley. A few sieved out of the shell-pockets, 

 Strandhill. Though this species is not rare locally in S.W. Kerry, 

 it is more abundant in the north. We know nine stations for it 

 in Antrim alone, one well within the city boundary, Belfast. 



Bythlnla ten tacu lata, L. — Common ; Rosses Point, Lough Gill, 

 river at Collooney, Glencar Lake. 



Hydrobia ulvae, Penn. — A few in the shell-pockets. 



Valvata pisci nails, Mull. — Lissadill, common in Lough Gill and 

 river near Collooney, dredged in myriads in Chara with Bythinia and 

 a few of the next in Glencar Lake. 



V. cristata. Mull.— Common in river at Union Wood, Collooney ; 

 Rosses Point ; a few only in the Glencar Lake dredgings. 



Ncritlna fluvlatllls, L.— Common in Lough Gill; in Glencar Lake 

 (both counties). This is the most northerly habitat yet known for 

 this species in Ireland, where its distribution is mainly westerly. 



Sphaeriunn corneum, L — Lough Gill, common but not large ; river 

 near Collooney ; pond at Belladrihid ; Glencar Lake dredgings; very 

 large obese form in lakelet at Rosses Point, where it was common in 

 submerged moss on margin, in an inch or two of water only. 



