44 NELSON AND TAYLOR : ON YORKSHIRE MOLLUSCA. 



obliquus De Kay are considered synonymous with P. deflectus, 



by Mr. Binney. 



12. Lower Calder — Very fine in a pond at Sandal near Wakefield, J.H. ! 



Planorbis parvus Say. 



Planorbis vermiciilaris Gould ! 

 Planorbis glaber Jeffreys ! 

 Planorbis concavus Anthony. 

 Planorbis elevatus Adams. 

 Planorbis cup^cola Von Gall. 

 Planorbis Moquini Req. 

 Planorbis regularis Plartm. 



Very local, but widely diffused. 



This species must now be known as Planorbis parvus Say, 

 instead oi P. glaber Jeif., by which name it has been so generally 

 known in England. Dr. Jeffreys himself acknowledged that 

 the two names represent the same species. We add to the 

 synonymy the P. vermiciilaris of Gould, of which species we 

 have received specimens from Oregon, undistinguishable from 

 our English examples oi P. glaber. Mr. Binney places^, concavus 

 Anthony, and P. elevatus Adams as synonyms of P. parvus. 

 Dr. Kobelt adds P. cup<zcola Von Gall., and P. Moqimii 

 Requien ; and Prof. E. v. Martens has in addition P. regularis 

 Hartmann. 



7. Went Vale — Planorbis hzvis is found in a small fish-pond at Ackworth, 

 and although almost the whole district for two or three miles round — 

 and in some directions for five miles — has been diligently explored, 

 they have not been found in any other pond in the neighbourhood, 

 although they are there particularly abundant ; but no other shell 

 is to be found with them, except a few LimniEa peregra, J. W. 

 Watson, Nat., 1S54, p. 57 ; Ackworth, abundant in one small de- 

 populated fish-pond, adhering to Potaniogeton crispus ; some 

 strange monstrosities occur, C.A., Nat., 1854 ; abundant in a fish- 

 pond in Ackworth Park, and there only, C.A., 1874 ; Ackworth ! 

 a few sjjecimens in a pond on the right hand side of the road past 

 Wakefield quarry, near Nostel, \V. E. Brown ; a few in dykes on 

 both sides of the road between Smeaton and Campsall, J.W. ; in 

 Hepworth's pond near Low Ackworth, G. F. Linney. 



Trans. Y.N.U., 1883 (pub. 1885). Series C 



