278 JOURNAL OF CONCHOLOGY. 



A LIST OF THE SHELLS OF THE "LOWER TEES" 

 DISTRICT, YORKSHIRE. 



By CHARLES ASHFORD. 



J. W. W. =JoHN W. Watson. C. A. = Charles Ashford. 

 Airyholme Wood is between the village of Ayton and Roseberry Topping. 



Sphaerium corneum L. Generally distributed in the Lower 



Tees district (C. A. and J. W. W.). 

 S. lacustre Mull. Pretty general in the neighbourhood Ayton 



and Stokesley (J. W. W.). 

 Pisidium amnicum Mull. General (J. W. W.). 

 P. fontinale var. pulchella Jenyns. Very general round about 



Ayton (J. W. W.). 

 P. fontinale var. cinerea Alder. In running streams near 



Guisborough (J. W. W.). " 



P. pusillum Gmelin. Generally distributed (J. W. W.). 

 Anodonta cygnea L. General in south of district (J. W. W.). 

 Neritina fluviatilis L. Ballast hills near Middlesbrough 



(J.W.W., alien?). 

 Bythinia tentaculata L. General (J. W. W.). Pond near 



Redcar (C. A.). 

 B. Leach ii Shepp. Not nearer than Billingham Beck, S. Durham 



(J. W. W.). 

 Valvata piscinalis Mull. Not nearer than Billingham Beck, 



S. Durham (J. W. W.). 

 V. cristata Mull. Ditches near Gt. Ayton (J. W. W.). 

 Planorbis nautileus L. Near Middlesbrough (J. W. W.). 



On duckweed in pond, Coatham marshes (C. A). 

 P. albus Mull. Ditches near Gt. Ayton (J. W. W.). 

 P. glaber Jeffr. Ponds near Gt. Ayton (J. W. W.). 

 P. spirorbis Mull. General in the district (J. W. W.). 



J.C, iii., January, 1882 



