108 EXPEDITION OF THE "ALBATROSS," 1899-1'JOU. 



ence of the belts of bath^inetrical range of pelagic organisms invented 

 by Haeckel, based by him on data of the " Challenger." On the contrary, 

 I would interpret the data of the " Challenger," as well as the results I 

 have obtained in this and former expeditions, and those of the "National" 

 and " Valdivia" Expedition, as showing that within a certain distance from 

 the bottom, at sea, far from continental areas, there is a free-swimming 

 fauna related to that found on the bottom ; and that the pelagic fauna, 

 so-called, away from the continents, where the surface fauna is a mixture 

 of shore embrj'os and of pelagic animals derived from a comparatively 

 short distance from the shore, extends to a very limited depth from the 

 surface, — three hundred fathoms, or thereabout, indicating, from our present 

 knowledge, the limit to which the so-called intermediate fauna extends ; 

 many of its members coming occasionally to the surface or near it, and 

 the members of the surface fauna often dropping to considerable depths 

 from disturbing atmospheric causes ; near the surface these two faimte thus 

 become mixed to a certain extent. From my earlier observations, I was 

 inclined to place the lower limit of bathymetrical range of tlie surface 

 organisms somewhat too high, though even at that limit the pelagic 

 fauna is already greatly reduced in numbers, as has been noticed also by 

 subsequent observers. 



Nkwport, R. I. 

 Ocloher 25, 1900. 



