VI PREFACE 



In organizing and carrying out the project, splendid cooperation and 

 valuable suggestions were received from the contributors to the book. The 

 writer wishes to express his profound thanks to them for their continuous 

 interest, the great amount of work required to prepare the articles, and their 

 constructive criticism. Waldo L. Schmitt, head curator, U. S. National 

 Museum, and William Randolph Taylor showed unremitting interest in the 

 progress of the work, gave valuable advice in the formulation of the plan, and 

 were most helpful in suggesting some of the authors and persuading them to 

 undertake the review of various groups. My thanks are also due Richard S. 

 Green, Chief, Shellfish Branch, Division of Sanitation, Public Health Service 

 and A. F. Bartsch, biologist. Division of Water Pollution Control, Public 

 Health Service, for organizing the material in the chapter on water pollution; 

 to William S. von Arx of the Woods Hole Oceanographic Institution, Francis P. 

 Shepard of Scripps Institution of Oceanography, Remington Kellogg, 

 Director, U. S. National Museum, Frederick C. Lincoln, assistant to the 

 Director, Fish and Wildlife Service, and Isaac Ginsburg, Ichthyologist, Fish 

 and Wildlife Service, for valuable comments and constructive criticism of 

 certain parts of the book. 



The work of Mrs. Margaret M. Quattromini in retyping the text and ar- 

 ranging the bibliographies is gratefully acknowledged. 



Paul S. Galtsoff, 

 Fishery Research Biologist. 



