CN 



DEAR SIR: 



Your i)ul)licati(ins on ("oncholojjy, (bolli scinuntr mcinoir.s, 

 ;'ud extracts from t,ho Proceedings of Societies,) are reiiiicsted in cxclinnne ; 

 provided they do not exceed my o^vn in vidnc. 



For convenience in niakiuu,' tliesi' cxchaniies, 1 sliall incorporate i:i 

 one volume, with an index, my pidjjicalions for eacli year. 



An equivalent in American Species will he returned for (f.O]i ('oilec- 

 tions of foreign Marine, Fresh Water, or Land Shells. Authors' exam- 

 ples are particularly solicited. All hooks or specimens intended for nu- 

 should accompany the puhlications of your Society, when they make 

 .■shipments to our Academy. Bff this tiirauH Iirari/ freif/hf r./ntrf/ex wiUbr- 

 n voided. 



ir3= ADDBESS YOUR PACKAGES TO 



GEO. W. TRYON, Jr., 



ACADEMY OF NATURAL SCIEIVCES. 



Pim.ADKLPIlIA, PkNNA. 



I 



