59.15.2:4.36 



CONTRIBUTIONS FROM THE BERMUDA BIOLOGICAL STATION 



FOR RESEARCH. 



No. 59. 



ON THE PERIODIC SHOREWARD MIGRATIONS OF 

 TROPICAL NUDIBRANCHS. 



Br W. J. CROZIER. 



FROM THE AMERICAN NATURALIST, VOL. LI, No. 606. 



CAMBRIDGE, MASS., U.S.A. 

 JUNE, 1917. 



