11 THE NAUTILUS. 



BACK VOLUMES OF THE NAUTILUS. 



Vol. IV. May, 1890 to April, 1891, . $1.00 

 Vol. V. May, 1891 to April, 1892, . 1.00 

 Vol. VI. May, 1892 to April, 1893, . 1.00 

 Vol. VII. May, 1893 to April, 1894, . 1.00 

 Vol. VIII. May, 1894 to April, 1895. . 1.00 

 Vol. IX. May, 1895 to April, 1896. . 1.00 

 Vol. X. May, 1896 to April, 1897. . 1.00 

 Of Vols. I and II, which were known as the " Concholog ist' s Ex- 

 change," and Vol. Ill of THE NAUTILUS, we can furnish odd 

 numbers only. 



Extras of August and September number, (1895) containing an 

 Index to the Conchologists' Exchange for binding with the latter, 

 will be furnished at 10 cents per copy. 



Advertisements will be inserted at the rate of $1.OO per 

 inch for each insertion in advance. Smaller space in propor- 

 tion. A discount of 25 per cent, will be made on insertions of 

 six months or longer. In order to have the paper out promptly, 

 " copy " is put in the printer's hands on the 20th of each 

 month. 



Address, C. W. JOHNSON, 



WAGNER FREE INSTITUTE, 



Philadelphia, Pa. 



EXCHANGES, 



The following space is to be given to exchanges. Notices not 

 exceeding three lines, will be free to subscribers as long as our 

 limit of space will allow. 



FOR EXCHANGE : Planorbis naidileus Lin., P. aroostookensensis 

 Pils. and other land and fresh water shells of Northern Maine. For 

 land, fresh water and marine shells. 



OLOF O. NYLANDER, Caribou, Maine. 



FOR EXCHANGE : Land and fresh water shells of southern Wis. 

 for some from other localities. WANTED : Unio tuberculatm opals, 

 fine crystals, minerals, fossils or marine curios. 



MRS. E. C. WISWALL, Kenosha, Wis. 



FOR EXCHANGE: Land, fresh water and marine shells, (many 

 rare species offered) for species not in my collection. List first. 



C. F. ANCEY, admiuistrateur adjoint, Dra-el Mizan, Algeria. 

 FOR EXCHANGE : About 70 species of Unios including many 

 rare southern varieties. W. S. STRODE, M. D., Lewiston, 111. 



WANTED: North American Linnceidce in sets from various local- 

 ities. OFFERED : Marine shells from Florida and land and fresh 

 water shells from Chicago. FRANK C. BAKER, 



Academy of Sciences, Lincoln Park, Chicago, 111. 



WANTED: No. 7, Vol. Ill, of THE NAUTILUS. OFFERED : 

 Other Conchological papers. 



M. M. SCHEPMANN, Rhoon near Rotterdam, Netherland. 



