70 bulletin: museum of comparative zoology. 



trawl had been working at 2235 and at 2222 fathoms. Both Moseley 

 and Herdman described this interesting Ascidian as attached to the 

 bottom by a small peduncle. While the presence of the peduncle can- 

 not be denied, yet its attachment, if attached at all, must be of the 

 slightest. Its transparent slightly translucent body, with its eight large 

 lobes, suggesting rather a pelagic type than a sedentary form. This 

 Ascidian was discovered by the " Challenger " west of Valparaiso.^ 



Mr. Chamberlain made two daily observations of the density of the 

 water, and found the same discrepancies between our observations and 

 those of 1891 with those given by the " Challenger " and in the Deutsche 

 Seewarte Atlas of the Pacific Ocean. "Whenever we took a serial tem- 

 perature, he also determined the density at 800 fathoms. We occupied six 

 stations for the serial temperatures, two on the western termini of the lines 

 normal to the coast across the great Peruvian current, two in the centre 

 of the current, and two at a moderate distance from the coast. These 

 serials developed an unusually rapid drop in the temperature between 

 the surface and 50 fathoms, nearly 12°, at the western extremity of the 

 northern line, the temperature having dropped from 71.7° at the surface 

 to 59.2°. At 200 fathoms it was 51°, and at 600 fathoms it had dropped 

 to 40.7°, the bottom temperature at 2005 fathoms being 36.4°. The 

 temperature of the station in the central part of the current in 2235 

 fathoms agreed with the western series. At the eastern part of the line 

 in 2222 fathoms, with a bottom temperature of 36.4°, the surface being 

 only 67'^, we found again a close agreement at 50 and 100 fathoms, the 

 lower depths at 400 and 600 fathoms being from one to two degrees 

 warmer than the outer temperatures. On taking a serial from the sur- 

 face to 100 fathoms, we found that the greatest drop in temperature took 

 place between 5 and 30 fathoms. 



The temperatures of a line running due Avest from Callao showed a 

 very close agreement both at the western end of the line about 780 

 miles from the coast and in the central part of the line, as well as in the 

 shore station about 80 miles from the coast in 3209 fathoms. The bot- 

 tom temperature in nearly all the depths we sounded was 36°, a high 

 temperature for that depth. I do not make at present any comparison 

 with the serials taken in the Pananiic district in 1891 until we shall 

 have completed our lines to the south and to the west. 



We leave for Easter Island on the 3d of December, where we shall 



1 In the Albatross Tropical Pacific Expedition (1899-1900) Octacnemus was 

 obtained in tlie tow net from less than 150 fathoms at Station 15, Lat. 4° 35' N., 

 Long. 136° 54' W. 



