154 
bulletin of the bureau of fisheries. 
While many dark puzzles have been solved, and many questions, raised fifteen 
years or more ago, can now be answered with assurance, no enterprising or resourceful 
worker need be told that the field is still fertile for fuller or more exact researches in 
many directions. We hope that some of these subjects will be suggested by the imper- 
fections of the present work when attention is not called to them directly. 
F. H. HERRICK. 
Cleveland, Ohio. 
