40 



Papers from the Marine Biological Laboratory at Tortugas. 



Below 100 fathoms the conditions are closely similar at both stations, 

 as far as the observations go; the salinity decreases fairly rapidly to 400 

 fathoms and then more slowly to the bottom. 



The temperatures decrease rapidly and uniformly from the surface to 

 about 500 fathoms, then more slowly to the bottom. 



35.0 



37.0 



(/) 



100 



200 



300 



400 



O 



X 



< 500 



600 



700 



800 



900 



Fig. 4. — Salinity curves. 



Continuous line = Station i. 



Broken line = Station 2. 



Dotted line =Michael Sars Station No. 65. 



There is practically no thermocline (German "sprungschicht") in the 

 temperature at any depth and only a poorly marked one, confined to the 

 upper stratum, in salinity. 



The absence of a temperature thermocline is remarkable (see the curves 

 for the two stations, and the two from the Michael Sars and the German 

 South Pole Expedition, drawn for comparison). 



In general, below about 250 fathoms the temperatures and salinities 

 agree with the nearest stations of the Michael Sars in the open Atlantic; 



