64 PROCEEDINGS OF THE CONCHOLOGICAL SOCIETY. 



and pfeifferi and virescens as varieties of elegans. The claims of 

 some Other species or varieties that have been brought forward 

 can scarcely be considered as well established. 



Planorbis fontanus. — To avoid confusion we think it 

 better in this case not to follow strict priority. 



Valvata piscinalis v. antiqua Sow. is now considered 

 to be practically the form named by Dr. Jeffreys v. suhcylindrica, 

 and as Sowerby's name has priority it has been adopted in the list. 



Under Anodonta cygnea we have introduced as a form 

 worthy of note the var. stagnalis, which is a form nearly ap- 

 proaching a circular outline ; the var. areuaria represents the 

 extreme form of zeUensis ; the var. zellensis, as ordinarily under- 

 stood, is the true specific type of A. cyg?tea. 



A. anatina we also still retain as distinct from A. cygnea, 

 there being some reasons for maintaining it as a separate species. 



Unio tumidus v. mulleri Rossm. — This variety, which 

 is characterised by its very ovoid outline, is added to our list. 

 It was found by Mr. H. E. Quilter in Groby Pool, Leicester- 

 shire, during 1885. 



Sphasrium ovale Fer. has disappeared from the list as 

 a species, Gray's name of pallidum superseding it, as we are 

 inclined to believe that an uncapped or indistinctly capped form 

 of S. lacustre is the true S. ovale of Ferussac, and we have 

 therefore placed it as a variety under that species. 



The P. roseum of Scholtz is not considered to be the 

 same as Jeffreys' species by those who have made a special study 

 of the group, and Held's name of niilium is therefore substituted 

 as our species is considered to be referable to that form. A variety 

 alpestris is also included, as specimens found by Mr. E. Pickard, 

 of Mansfield, have been considered by Clessin to represent his 

 variety. 



Other minor modifications hardly call for special remark, 

 but in all changes we have been solely guided by the desire to 

 render the list more useful in showing the affinities of the 

 various species and groups. 



J.C., vii., April, iSg?. 



