H. pollard: laxd and freshwater shells. 



137 



Helix pulchella var. costata Mill]. West Cliff, with type, 1878 



(H.C.); and in 1883 (H.P.). 

 Bulimus obscurus Miill. Common in hedgerows, in the Factory 



fields, in May 1877 (H.P.). 

 Bulimus obscurus var. alba. One specimen taken with type in 



hedgerow in the Factory Fields, 1879 (H.P.). This is only the 



second record for Yorkshire. 

 Pupa umbilicata Drap. Plentiful near Ruswarp in 1878 (H.C.). 

 Pupa marginata Drap. One specimen found on slopes of West 



Chff, in 1883 (H.P.). 

 Clausilia rugosa Drap. Collected rarely near Ruswarp, in 1878 (H.C.); 



commonly a short distance from Sleights Station, in 1883 (H.P.) ; 

 and in abundance near Sandsend, in August 1886 (H.P.). 

 Clausilia laminata Mont. Reported by Mr. J. T. Sewell as occurring 



in beech-woods. 



Cochlicopa lubrica Miill. West Cliff and Saltwick, May 1877 



(H.P.) ; and near Whitby Abbey, August 1885 (Y.N.U.). 

 Cochlicopa lubrica var. lubricoides Fer. West Cliff, 1878 (H.C.) ; 



and in August 1883 (H.P.). 

 Pisidium amnicum Miill. Amongst freshwater algje in a pond near 



Saltwick, in 1879 (H.C.). 

 Pisidium pusillum GmeHn. In a pond near Saltwick in 1879 (H.C.) ; 



and Whitby, August 1885 (Y.N.U.). 

 Unio margaritifer L. Abundant in the river Esk, near Lealholm 



Bridge, in 1878 (H.C.) ; and at Cruckley Gill, in 1879 (H.C). 

 TJnio margaritifer var. sinuata Lam. Sparingly, with type, in 



river Esk at Lealholm Bridge, in 1878, and at Cruckley Gill, 



in 1879 (H.C). 



On collecting this mussel in the Esk, in 1885, Mr. Henry 

 Crowther noticed that nearly every specimen had a parasitic 

 worm in the oval portion of the digestive tract. 

 Planorbis nitidus Miill. Reported by Mr. J. T. Sewell to occur 

 in the Abbey Pond, but I have not yet searched there for it 

 (H.P.). Messrs. Coates, Hudson, and Roebuck, when fishing 

 the Abbey Pond in August 1885, found only the next species 

 (/V. nautiletis). 



Planorbis nautileus L. Abundant in the Abbey Pond, it being 



apparently the only molluscan inhabitant, August 1885 (Y.N.U.); 



coast near Whitby (J.W. and G.R. in Part viii, Series C, 1885, 



Trans. Yorks. Nat. Union). 

 Planorbis complanatus L. On the coast near Whitby, in 1875 



(G. Roberts, in Trans. Yorks. Nat. Union, Part ix, Series C, 



1886). 



May 1887. 



