NELSON AND TAYLOR : ON YORKSHIRE MOLLUSCA. 29 



Canal near Gateforth ! and near Burton Hall ! Snaith, R.D.M. ; 

 dykes about Hambleton ! Breighton, J.D.B. 



5. Hatfield and r/joz-we— Abundant in a ditch parallel with Black Bank 



Drain, W.D.R. ! 



6. Trent — Conisborough, J.W. 



7. Went Vale — In a stream running from the pool, Askern I common in a 



ditch in Cowick Park, W.D.R. ! Pontefract, J.C. ; sparingly in 

 the River Went, W. E. Brown ; a pond near Went Bridge, Hugh 

 Richardson ; in Ackworth School Canal, the Mill Dam Dyke, 

 and Plantation Mill Dam, G. F. Linney ; abundant at Ack- 

 worth, invariably covered with an earthy incrustation, C.A. 



10. Coins — Abundant in the canal at Huddersfield, J.Wh. 



11. Upper Calder — Hahfax, H.C. ) abundant in canal at Elland, J.Wli. 



12. Lower Calder — Common throughout the Wakefield district, J.H. j 



abundant in the Wakefield and Barnsley Canal near Wakefield, 

 H.P., and common, but small, at Royston ! New Miller Dam, 

 J.W. ; Pond at Normanton ! very abundant in mill stream at 

 Wintersett, W. E. Brown. 



13. Airedale — Leeds and Liverpool Canal at Armley ! Kirkstall ! Newlay !• 



Calverley ! Saltaire ! Bingley ! and Micklethwaite ! Frizinghall 

 Dam, W. West, of Bradford ! Aire and Calder Canal at Oulton ! 

 stream at Allerton Bywater ! common at Lofthouse, G. Roberts. 



17. Wensleydale — Ponds at Staveley ! common in ditches, and occasion- 



ally in the River Ure near Hackfall, J. D. ; Canal at Ripon, J. 

 Ingleby ! one dead shell in a horse pond at Jerveaulx Abbey, 

 W.D.R. ! Snape, H.C. ! one in a pond at Masham, H.P. 



18. Swaledale — Common in ditches and stagnant ponds about Thirsk, 



J. H. Davies, 1855. 

 20. Lower Tees — General in the district, J. W. Watson ; Pond near Redcar, 

 C.A.; Beck between Redcar and Marske, C.A. 



22. Upper Derwent — Scarborough, W.B, and J. H. Ashford. 



23. Chalk Wolds — Abundant and generally distributed around Hull, J. D.B. ; 



fine in Long Lane, J.D.B. ; common at Figham, J.D.B. ; River 

 Hull, J.D.B. ; Leckonfield Moat, J.D.B. ; Swinemoor, J.D.B. ; 

 Burlington, J.S.G. ; Londesborough, J.D.B. ; plentiful in the 

 River Hull at Driffield, L .B. Ross ! 



24. Holderness — Ditch near Hornsea Bridge, J.D.B. ; Leven Canal, J.D.B.; 



Common in Hornsea Mere, W.D.R.! plentiful in the river near 

 Foston, L. B. Ross ! 



Var. excavata Jeffr. 



7. Went Vale— Askern, J.C. 

 12. Lower Calder — New Miller Dam, J.W. ; Kirkthorpe, J.H, 



