GEOLOGY OF THE KLONDIKE GOLD FIELDS. 311 



mollusk from the upper Yukon, and to all inquiries regarding the 

 existence of shellfish in this northern water invariably a negative 

 replv was received. Only on that day did I again obtain success 



in my malacological etfort, the almost icy waters rewarding my 

 search with a single specimen— unfortunately subsequently lost— o'^f 

 a Bythinella, or some closely related type, so that even to-day my 



