KELSON AND TAVLOR : ON YORKSHIRE MOLLUSCA. 9 



3. Vale of Ko;-,V— River Foss, York, W.H.B. 

 8. Dea/77S— Canal, Barnsley ! River Don, Doncaster, H-F.P. 

 10. Colne — Elland (now extinct) J. C. 



12. Low 31- C aid 31- — New Miller Dam, J. W. Canal, Normanton ! Canal at 



Heath ! 



13. Airedale — Leeds & Liverpool Canal at Bingley ! Shipley, H.P.,Armley! 



Leeds ! 



22. Z?e/'we/?f— Scarbro', W. B. 



Sphaerium ovale, (Fer.) 



Cyclas transversa, Say. 

 Cyclas constricta, Anthony. 



This elegant shell is of a type found in South America and 

 West Indies ; it is identical with S. transversiim. Say, and is sup- 

 posed to have been introduced into this country. 



Mr. Anthony's C. constricta is a malformed specimen of this 

 species, with the valves constricted by a furrow up the centre of 

 each valve. 



Dr. Gray supposed this species to be allied to S. rhomboiJeum, 

 Say, an error pointed out by Dr. Jeffreys, that species being very 

 near to if not identical with S. corneum, 

 4. Number— Goole, R.W.I\L 

 8. Dearae— Canal at Barnsley ! 

 12. Lower Calder — Canal at Normanton ! Brighouse ! 



Sphserium lacustre, (Milll.) 



Cyclas partumeia, Say ! 

 Cyclas securis. Prime. ■ 

 Cyclas truncata, Linsley. 



Dr. Jeffre3's regards C. ;partumeiitm, Say, as a synonym of this 

 species, a view in which we coincide. He also considers S. 

 truncatiiin, Linsley, as a variety. 



From a study and comparison of the description of Z. 

 lenticula, Gould, we are inclined to regard it also as another form 

 of S. lacustre. 



A variety found near Huddersfield by Mr. Whitwham and 

 submitted to us, closely agrees with the description of Prime's 



