Jeffreys gives fourteen varieties. Some of these may clearly be 

 attributed to local circumstances. There are some stated to have 

 been procured from rivers, others from lakes, others from 

 marshes by the sea coast, and others again have been "thrown 

 up by the tide at the mouth of rivers". The most extraordinary 

 variety (not confined to this species) in my humble opinion is 

 decoUata, in which the "shell is more or less eroded, spire truncate" 

 so that the fact of a shell being eroded gives it the title to rank as 

 a variety!. In his Introduction p. II, Mr. Jeffreys gives several 

 reasons which may account ior erosion. I have noticed the erosion 

 in specimens of L. stagnalis kept in confinement in my aquarium, 

 which in course of time have been converted by erosion (by what- 

 ever cause produced) into L. stagnalis var decoUata, a variety which 

 I perceive is unknown to Mr Jeffreys. 



But my paper has already exceeded the limits which I intended 

 so that I must leave the examination of the genera and species to 

 your readers, and I shall be very glad if some of them can help 

 me to remove the difficulties whieh perplex my mind as to what 

 really constitutes the difference between a species and a variety, 

 and if they will also make clear to me what is the principal upon 

 which the differences are formed 



THE GENUS EATON I A. 



Our readers will find, on referring to the Bibliographical Notice 

 of New Shells from Kerguelen's Island at p. 86 of this number, 

 a mention of a new Genus which has been characterized under the 

 name of Eaton ia by Mr. Edgar A. Smith. 



The name has however been pre-occupied by Hall in 1859 to 

 designate a genus of fossil Brachiopoda, in compliment to the 

 American Prof Amos Eaton. Vide — Ralph Tate's appendix to 

 Woodward's "Manual of the Mollusca", p. 59. 



Host 8vo. cloth, with coloured Illustrations ; 

 Price 7/6. 



RAMBLES IN SEARCH of SHELLS; 



(LAND and FRESHWATER) 



BY 



James Edmund Harting, F.L.S., F.Z.S., 



AUTHOR OF 



"%}xt CDmtthology of ^liaktapew," etc., etc. 

 Landoa : JOHN VAN VOORST, 1 Paternoster Sow 



