VI PREFACE 



of the sea; to Dr. Henry B. Ward, who looked over the por- 

 tion deahng with the biology of fresh waters; and to Dr. 

 Charles W. Richmond, Dr. Alexander Wetmore, Dr. Thomas 

 Barbour, Dr. Albert Mann, Dr. Waldo L. Schmitt, Mr. Ray- 

 mond C. Shannon, Mr. Herbert S. Barber and Mr. Clarence 

 R. Shoemaker to whom certain sections were referred. 



Messrs. Wetmore, Shannon, A. N. Caudell and Barber were 

 so generous as to provide me with hitherto unpublished in- 

 formation from their personal notes, and I owe to Mr. Barber 

 the remarkable photographs of flies and moths reproduced on 

 the plates. 



For the most part the figures are taken from previous 

 publications by other authors, to whom they are accredited. 

 Those with the designation "Bur. Ent." are from the publi- 

 cations of the Bureau of Entomology, Department of Agri- 

 culture; "Bur. Fish." indicates the Bureau of Fisheries, 

 Department of Commerce; "U. S. N. M." stands for the United 

 States National Museum; and "S.I." for the Smithsonian 

 Institution. 



To Mr. Samuel Henshaw, the Director of the Museum of 

 Comparative Zoology at Cambridge, Massachusetts, I am 

 deeply indebted for permission to reproduce those figures 

 which are taken from the publications of that institution, and 

 I am under similar obligations to the Cambridge University 

 Press, of Cambridge, England. 



Except for those portraying insects the plates are all from 

 photographs of living animals taken at the National Zoological 

 Park (Smithsonian Institution), W^ashington, D. C, which 

 were most generously given me by the late Mr. Ned Hollister, 

 the Superintendent. 



In the preparation of the text figures I have had the able 

 assistance of Miss Doris M. Cochran, and for aid in the biblio- 

 graphic work upon the insects I am greatly indebted to Miss 

 Frances M. Appleby. 



April i6, IQ25 Austin H. Clark 



