its design : the imperfection of human judgment, the uncertainty ai-ising from 

 paucity of material in some cases, in others, perhaps, tlie bewilderment caused 

 by its redundancy, are fruitful sources uf error which will occasionally waylaj' 

 and mislead the most honest, thorough and patient investigator. 1 cannot 

 hope to escape them ; but I shall take note of all corrections, as well as of sucli 

 additional information as may hereafter become accessible to me, in order that 

 these may be incorporated in appendices, or perhaps in additional volumes, to 

 be published from time to time, whenever tlie accumulation of such material 

 may render them necessary. 



1 feel that the work I propose to undertake is a worthy one ; that its com- 

 pletion will enable the Conchologist/o?- the first time to identify and to learn the 

 history of all the species in liis cabinet without the necessity of consulting 

 many extensive and costly monographies, besides thousands of fugitive papers. 

 Towards the completion of this task I ask the sympathy and aid of .all 

 interested in Conchological pursuits. 



GEORGE W. TRYON, Jr. 



