26 JOURNAL OF CONCHOLOGY, VOL. II, NO. I, JANUARY, I904. 



by entangling grains of sand and particles of clay, have ultimately formed a large 

 knob, which gives the shells a most singular appearance, and has probably some 

 value as a means of protective concealment. The body whorl of the shells is quite 

 clean, and would appear to have been buried in the sandy mud, the apex alone 

 protruding. 



By Mr. C. Oldham : Anodonta cygnea, Tatton Mere, Cheshire, showing curious 

 malformation due to injury to mantle at an early stage of growth. 



By W. E. Hoyle : Sepia burnupi, the type specimens. 



On behalf of Mr. F. J, Partridge : Vitrea rogersi, Dudley Castle, Worcestershire; 

 Ancyhis fluviatitis , Innisfallen, Killarney (a new record for Kerry) ; and a series of 

 North Devon MoUusca, including thirty-eight new county records. 



On behalf of Mr. L. E. Adams : Helix pomatia, from open downs near Reigate, 

 Surrey, probably gnawed by rats. 



In illustration of Mr. Hall's paper, a series of locality sets ot Anodonta cygnea 

 was exhibited by Messrs. C. Oldham, W. J. Hall, J. W. Baldwin, J. T. Wads- 

 worth, J. W. Jackson, J. W. Vaughan, and R. Standen ; the latter also showed 

 mounted sets of Glochidia (both dry and in situ upon fins and tail of Stickleback) ; 

 and young shells in earliest stages of growth after passing the Glochidia stage. 



It was decided to hold the following 



Special Exhibits at future Meetings : 

 January 13th, 1904 - - - Dreissensia polymorpha. 



February loth, 1904 - - - Limnaea palustris. 



March 9th, 1904. - - - British Pectens. 



A Standard of Value for Exchanges. — 1 think a discussion in ihe Journal 

 would be useful as to some recognized value system for exchanges. Most of our 

 collections are no doubt mainly built up by exchanges, but as a matter of honour and 

 morality we should no more desire to 'do' others than to be 'done' when exchanging. 

 Personally I have often found great generosity amongst brother conchologists, and I 

 trust have been not ungenerous myself either in exchanges or in giving. But I have 

 not infrequently found that would be or actual exchangers offer what practically 

 comes to the equivalent of "Twopence for your half-crown !" To-day, for example, 

 an American conchologist (who shall be nameless because, no doubt, he acts in 

 ignorance of comparative values) sends me two species which I find marked in an 

 American dealer's catalogue (a useful one obtainable from W. F. Webb, Albion, 

 New York) at 20 cents and 5 cents respectively. In exchange he would like certain 

 shells from Asia, which I find priced in another catalogue at from is. to 8s. How 

 many from this list of desiderata he wanted me to send I do not know ; but as I sent 

 him an Orthostylus priced at 4s. in exchange for his specimens which came altogether 

 to the value of 75 cents, I hope he will not be disappointed. Some time ago I drew 

 attention to the disappointment that ensued when in exchanging with continental 

 conchologists one received as distinct species shells hardly worthy of a varietal name 

 and belonging to a very common species. I suppose I have had H. virgata sent to 

 me under forty different names, and the same may be said to a somewhat less degree 

 of H. htcasi, H. pisana, &c. The late Mr. Layard used to feel strongly, and write 

 amusingly, about the desirability of the establishment of some sort of standard value 

 as a basis of exchange, and I think a correspondence in your columns on this point 

 would be useful.— [Rev.] J. W. Horsley {Read before the Society, May 13, 1903). 



