vol. XXIX1 

 1912 J 



Gross, The Yellow hilled Tropic-bird. 



49 



OBSERVATIONS ON THE YELLOW-BILLED TROPIC- 

 BIRD (PHAETHON AMERICANUS GRANT) AT THE 

 BERMUDA ISLANDS. 



BY ALFRED O. GROSS. ^ 



Plates III-XI. 



This paper is based upon studies made while at the Bermuda 

 Biological Station from June 17 to August 2, 1910, and from June 26 

 to August 5, 1911. It is a pleasure here to acknowledge my grati- 

 tude to Prof. E. L. Mark, director of the Bermuda Station, for 

 many valuable suggestions and for revising the manuscript. 



The geographical location of the Bermudas is unique, in that 

 they are in mid-ocean about seven hundred miles from the nearest 

 land. The longitude of the center of the group is 64° 39' 53" W., 



1 Contributions from the Bermuda Biological Station for Research, No. 23. 



