JOURNAL OF CONCHOLOGY. 1 7 



NATURE AND DEVELOPMENT OF THE HAIRS 

 OR BRISTLES ON SOME LAND AND FRESH- 

 WATER SHELLS, &c. 



By WILLIAM JEFFERY. 



Being his Valedictory Address as President of the Conchological Society 

 FOR THE Year 1885. 



Gentlemen, — Just about the time when you did me the 

 honour of electing me President of the Conchological Society, 

 the subject of the manner of formation and the uses of the 

 hairs or bristles with which the shells of some of our land 

 snails are covered had attracted my attention; and I went so 

 far as to ask our secretary (Mr. Bell) if any information had 

 been published on the subject. His reply was in the negative, 

 so far as he and Mr. Taylor were aware, and he advised me to 

 make the matter a subject of study. 



Since then I have been urged by these gentlemen, and 

 other members, to make it the subject of an address to you on 

 the termination of my year of office. 



I then felt that it would be out of my power altogether in 

 the short space of time at my disposal to do so, but having 

 paid some attention to the subject through the past summer, 

 I have, not without much diffidence, decided to lay before you 

 such ideas and facts as have occurred to me, with the hope 

 that they may lead to a farther elucidation of the subject, by 

 others, when once started. 



We have not many species to deal with. The late Dr. 

 Jeffieys notes this peculiarity in six species only, viz. Helix 

 rufescens. H. concinna, H. hispida, H. sericea, H, revelata, and 

 IT. obvoluta. 



