MOLLUSCA OF MID-WEST YORKSHIRE. 193 



P. contortus (L.). — Gisburn, plentiful ; Malham Tarn, abund- 

 ant ; .Staveley ; Askhara Bog, common ; Leventhorpe 

 pastures and Black Hills near Leeds ; Carlton near Snaith; 

 Barlow Common near Selby. 



P. contortus var. albida Jeff. — Castleford. 



Physa hypnorum (L.). — Wetherby; ditch near Castleford ; 

 Carlton near Snaith. 



P. fontinalis (L.). — Ripon Canal; Eavestone near Ripon ; 

 Staveley ; common at Askham Bog ; Carlton Pond near 

 Snaith; Bishop Dyke near Sherbuni ; stream at Allerton 

 Bywater; pond at Black Hills, Leeds; Tadcaster ; plenti- 

 ful at Gisburn ; Barlow Common near Selbv. 



Limn^a peregra MiilL, — Specimens shown from very 

 numerous localities about York, Wetherby, Leeds, Snaith, 

 Ripon, Harrogate, Shipley and Baildon, Castleford, Ilkley, 

 and other places, also from Ingleton, Gisburn, Bracewell, 

 Buckden and Starbotton, from the marsh at Malham Tarn, 

 and from Washburndale. Very variable and usually plentiful. 



L. peregra var. ovata Urap. — Pannal; canal at KirkstaU, &c.; 

 Gisburn ; Malham Tarn; Malham Cove; Fewston reservoir; 

 &c. 



L. peregra var. acuminata Jeff. — Malham; Bishop Thorn- 

 ton. 



L. auricularia (L.). — Canal, Ripon; Fewston reservoir; 

 river Aire near Bingley ; pond at Allerton Grange, Leeds ; 

 lower lake, Roundhay Park. 



L. stagnalis (L.). — Masham, ponds, large and fine; Wetherby; 

 Askham Bog; pond, Black Hills, near Leeds. 



L. stagnalis var. fragilis-variegata. — Common 'in Malham 

 Tarn. 



L. palustris (Miill.). — Gisburn, in pond ; numerous near the 

 river at Kilnsey in Upper Wharfedale ; Askham Bog; near 

 Ryther ; Carlton pond near Snaith ; canal, KirkstaU ; 

 Leventhorpe pastures near Leeds. 



L. palustris var. lacunosa Zgl. — Leventhorpe pastures. 



