NELSON AND TAYLOR : ON YORKSHIRE MOLLUSCA. 3 



results of an extended and careful study of the Pulmonate group, 

 to which our own observations have been more particularly 

 directed. 



We must also express our thanks to numerous friends, 

 especially to Mr. W. Denison Roebuck of Leeds, Dr. Parsons, 

 F.G.S., of Goole, and Mr. J. D. Butterell of Hull, for their kind 

 and prompt response to our request for co-operation. 



Localities not our own have affixed to them the initials of the 

 conchologist from whom we have received the information. AVe do 

 not however in any case pledge ourselves to the correctness of 

 the identification where the sign of verification (!) is not given. 



EXPLANATION OF INITIALS AFFIXED TO LOCALITIES. 



C. A.— Charles Ashford, of London (Q.^.C, i. 19). 



J.D.W.— J. Darker Butterell, of Hull, 



W.H.B.— W, H. Broadhead, of Leeds. 



J.B. — James Eeevers, of Leeds. 



W.B. — W. Bean, of Scarboro' (Theakston's Guide to Scarljoro'). 



T.W.B.— T. W. Bell, of Leeds. 



ILC. — Henry Crowther, of Leeds. 



J. C- — J. Conacher, junr., of Huddersfield. 



R.M.C.— R. M. Christy, of Brighton. 



J.Dal.— Rev. J. Dalton (Mag. N. H. and Nat. 1859). 



J. D. — John Dixon, of Leeds. 



D. and W. — Dixon and Watson, ' British Land and Freshwater Shells.' 



J.E. — J. Einmett, of Boston Spa. 



J.S.G.— J. S. Gibbons, M.B., of Southampton. 



J.G. — John Grassham, of Leeds. 



J. W.— Joseph Hebden, of Wakefield. 



R.W.M.— Rev. R. W. Maxwell, of Goole. 



H.P.— H, Pollard, of Leeds. 



L.P. — Lister Peace, of Huddersfield. 



H.F.P.— H, Franklin Parsons, M.D., F.G.S., of Goole. 



W.D.R.— W. Denison Roebuck, of Leeds. 



R.S. — Robert Scharff, of Bordeaux, 



H.S.— H. Shaw, of Leeds. 



A.P.T.— A. Peckett Taylor, of Mapplewell. 



G.T.— G. Taylor, of Wakefield. 



J.W — J. Wilcock, of Wakefield. 



J.Wh — J. Whitwham, of Huddersfield. 



