66 EXPEDITION OF THE " A&BATROSS," 1809-1900. 



31° 10' N., long. 125° W., and terminates at Tahiti off Pt. Venus about in lat. 

 17" 30' S., and long., 149' 30' W. That of the " Challenger" .starting north 

 of the Hawaiian Islands in lat. 38° 9' N., and long. lo6° 25' W., and 

 ending also at Tahiti, converges towards the line of the "Albatross," so that 

 we have an excellent opportunity of comparing the collections of the 

 "Challenger" in the central Pacific with those obtained liy the "Albatross" 

 from the great red-clay and manganese-nodule area of the Pacific Ocean 

 to the eastward. An examination of the results as recorded by Sir 

 John Murray,' and those which I here give from the trawling of the 

 "Albatross" show plainly that at great depths and far from continental 

 areas or insular })lateaux the bottom fauna of the great depths is compara- 

 tively poor except when the trawling is made in the line of the great 

 equatorial currents, where the bottom fauna receives a larger amount of 

 food, derived from the dead remains of the pelagic fauna falling to the 

 bottom. 



A similar increase in the number of animals brought up in the trawl 

 can also be noted in the hauls made by the "Challenger" on the line east 

 of Japan, while practically in the track of the great Japanese current sweep- 

 ing to the eastward. In marked contrasts to this line and to the results 

 obtained in the track of the equatorial current by the "Albatross" are the 

 scanty hauls obtained by the "Challenger" from the Admiralty Islands 

 north to Japan. 



The line of dredgings made from Tahiti to Valparaiso is also relatively 

 richer than the two principal lines across the deepest parts of the central 

 Pacific explored by the "Challenger" and "Albatross." That is in part 

 due to the nature of the bottom, which is often made up of Globigerina ooze, 

 and also undoubtedly to the fact that the eastern extension of the " Chal- 

 lenger " line from Tahiti was run in the northern extension of the basin of 

 the Southern Ocean, which, as is well known, has supplied a far richer deep- 

 water bottom fauna than that found in the intertropical areas of the Pacific. 



To facilitate the comparison between the results obtained in the Pacific 

 by the "Challenger" and those of the "Albatross" during her trip to the 



* In the General Summary of the " Challenger " results, and in the IJcep Sea Deposits (" Chal- 

 lenger " Expedition) hy Murray ami Henanl. 



