378 Dr. Gwyn Jeffreys on some 



the French species and varieties of Succinea which he so 

 admirably described and figured in the ' Journal de Conchy- 

 liologie ' for last year. It is a most laborious and exhaustive 

 monograph. This experienced author is a true man of science; 

 and I feel sure that he will not object to the critical remarks 

 which I venture to make from a point of view different from 

 his. I am aware and glad that lie does not follow the example 

 of certain of his countrymen in fabricating what they call 

 " new " species out of every trivial variety and local form. 

 No individual specimen can be precisely like another ; and 

 considerable allowance ought to be made for a difference of 

 conditions. The result of my investigations during a period 

 of at least half a century has been rather to reduce than 

 increase the number of species represented by abundant or 

 widely distributed forms. Now this is remarkably the case 

 with some land and freshwater Mollusca, including Succinea 

 and Lymnoea^ which are so prolific and inhabit watery places 

 with easy and various means of migration or transport. 



Having carefully examined Dr. Baudon's specimens of 

 reputed species of French Succinece^ and compared them with 

 specimens in my own collection of British shells, I would 

 assign those species as follows : — 



S. paj'vula, L. Vasc&l, = S. elegans, Risso ; var. ocAracea, 

 Betta. 



S. Baudoni, H. T>roi\Gt,^S. putrts, Linne ; dwarf form. 



S. acrambleia,J. Mabille, = 8.p)utris] vav. soUdula, Jeffreys. 



S. Pfeifferi, E.ossmassler,= /S'. elegans ; var. 



S. arenaria, Bouchard, = aS'. ohlongaj Draparnaud; var. 



S. hunnlis, H. Drouet, = /S*. oJ/on^a ; var. (ex exemplis mihi 

 ab auctore missis). 



S. Crosseana {Crossiana), Baudon, = /S^. ohlonga] var. 



8. breviuscula, Baudon, = S. ohlonga ; var. 



With respect, however, to S. virescens of Morelet, which 

 Baudon has apparently described under Morelet's name of S. 

 debiHsj I believe it is distinct from any of the three species 

 which I have acknowledged as British, viz. putris, elegans^ 

 and ohlonga. It should therefore be added to our native fauna. 

 This is my variety vitrea of S.j^utris, ' British Conchology,' 

 vol. i. p. 152. I lately found a specimen at St. Alban's, with 

 ;S^. pictris ; but unfortunately I had no time to examine the 

 animal, further than by noticing that it seemed to be of a 

 darker hue than that of S. putris or >S^. elegans. Mr. Henry 

 Groves has obligingly sent me a specimen of the shell, which 

 he had collected at Mitcham in Surrey. The other localities 

 which I have recorded are Carmarthenshire and Grassmere 



