3rO JOURNAL OF CONCHOLOGY. 



CONTRIBUTIONS TO A BETTER KNOWLEDGE 



OF THE 



LAND AND FRESHWATER SHELLS OF YORKSHIRE. 



By the Rev. W. C. HEY, M.A. 



Spheerium ovale. Abundant near Blue Bridge, York, 

 and larger than any specimens I have seen from other localities. 



S. rivicola. In company with S. ovale; very fine. 



S. lacustre. Large and abundant near Layerthorps, York, 

 in the Foss. Small specimens in narrow ditches near Clifton, 

 York. 



S. corneum. Abundant about York. Pale variety in 

 Askham Bog, York. 



Pisidium amnicum. In the Ouse and Foss at York. 



P. pulcheilum. Very abundant in shallow ditches near 

 York. 



P. pusillum. Similar localities. 



Unio tumidus. Very abundant in the Foss and in many 

 varieties. I notice particularly : — 



1. Thin, with green rays. 



2. Thick, short, rich brown in color. 



3. Incurved, like 7nargaritifer (scarce). 



4. Ponderous and very large, oblong in shape (scarce). 



U. pictorum. Common in the Ouse below York. 



Anodonta cygnea. Very abundant in the Foss at York. 

 I notice these varieties in particular : — • 



1. Very large, thin, pale olive-green. Foss Islands, where 



a large quantity of warm water enters the river. 



2. Very thin and broad, small. Ouse. 



J.C, ii., Oct., 1379 



