HEY: L. AND F. W. SHELLS OF YORKSHIRE. 311 



3. Var. radiata (a form of Jeffrey's anatina). Foss mouth, 



most lovely bright shells, rayed with a rich summer 

 green. 



4. Tumid, thick, narrow. Hornsea Mere. 



Neritina fluviatilis. The Ouse near Bishopthorpe. A 

 very dark variety. 



Paludina vivipara. Profusely abundant in the Ouse 

 below York. Very fine in the Foss. 



P. contecta. Fulford, near York. 



Bythinia Leachii. Abundant at one particular spot in 

 the river Foss above York. 



B. tentaculata. Foss, Askham Bog, &c. In the latter 

 place a variety with a white band occurs, and the specimens are 

 of unusual dimensions. 



Valvata cristata. In profusion in Dringhouses Bog, near 

 York. 



V. piscinalis. Foss, Askham, &c. 



Planorbis lineatus. In profusion in Dringhouses Bog, 

 near York. 



P. nitidus. In company with the last; also at Burlington. 

 P. nautileus. Ponds near York. 

 Var. cristata. Askham Bog. 



P. albus. Very fine in a pond close to the precipice (430 ft.) 

 of Bempton Cliff's ; also at York. 



P. spirorbis. In profusion in all ponds. ScalaiTorm 



distortion. Flambro' Head. 



P. carinatus. Askham Bog, common; also Seamer Mere, 

 near Scarbro'. 



P. complanatus. Very common about York, &=c. 



P. corneus. Askham Bog, Strensall Common, 6^c. 



