iPwM '-/*''"' ; :< .". ■'■'■"'. - -3 



Issued May 21, 1912. 



U. S. DEPARTMENT OF AGRICULTURE 



BIOLOGICAL SURVEY— BULLETIN No. 42 



HENRY W. HENSHAW, Chief 



REPORT 



OF AN 



EXPEDITION TO LAYSAN ISLAND 

 IN 1911 



UNDER THE JOINT AUSPICES OF THE UNITED STATES 



DEPARTMENT OF AGRICULTURE AND 



THE UNIVERSITY OF IOWA 



BY 



HOMER R. DILL 



Assistant Professor of Zoology in the State University of Iowa 



■ AND 



WM. ALANSON BRYAN 



Professor of Zoology in the College of Hawaii 



WASHINGTON 



GOVERNMENT PRINTING OFFICE 



1912 



