218 THE ATLANTIC. [chap. iv. 



The serial temperature sounding gave a bottom temperature of 

 0°-0 C. ; at 1Y25 the temperature was l°-0 C, at 600 fathoms 

 3°-0 C, and at 50 fathoms 20°-0 C. The trawl was not very 

 successful, but it brought up a few things of some interest, 

 among them an example of a small sea-urchin {Aceste hellidif- 

 era), of which we had previously taken single specimens at 

 widely different stations, off the coast of Nova Scotia, near 

 Gomera Island, near New Zealand, and near Japan. The bot- 

 tom was chiefly river-mud, with very little carbonate of lime. 



On the following day we sounded in 2800 fathoms, and again 

 lowered the trawl. The bottom was a grayish mud with little 

 or no carbonate of lime, and the bottom temperature was — 0°"4 

 C. The trawl-line parted near the ship in heaving in. 



On the 1st of March we proceeded on our course, and on the 

 2d we sounded in 2650 fathoms with a bottom of gray mud and 

 a bottom temperature of — 0°-4 C. The trawl was put over, 

 and a series of temperature observations were taken to 1500 

 fathoms. This sounding is very instructive : the isotherm of 

 3° C. is found at 600 fatlioms, so that we have a mass of water 

 at a lower temperature than 3° C. 2000 fathoms in thickness ; 

 2°-5 C. occurs at 1900 fathoms, and zero at 2400. A very mark- 

 ed hump on the curve which extends from a depth of 125 fath- 

 oms to a depth of 255 fathoms, and corresponds with the wide 

 spaces between the isotherms of 15° C. and 6° C, evidently in- 

 dicates the position and volume of the Brazil Current, the south- 

 ern deflection of the equatorial current after its bifurcation at 

 Cape St. Roque. The trawl came up containing an unusually 

 large number of organisms for this depth, including two speci- 

 mens of an undescribed species of Eujplectella, some corals, sev- 

 eral echinoderms illustrating three of the orders, some beautiful 

 examples of a sjDecies of Stylifer commensal on one of the holo- 

 thurians, and several fishes. 



Next day we sounded in 2775 fathoms, and took temperature 

 soundings. This series presented a marked difference from that 



