NARRATIVE OF THE CRUISE. 



289 



CHAPTER VIII. 



Cape of Good Hope to Prince Edward and Marion IsWs-The Crinoidea and Mvzostomida-The Cro.et Wands- 



I lie Petrels— Arrival at Kerguelen. 



Cape of Good Hope to Prince Edward and Marion Islands. 



OK the 17th December 1873, the Challenger left Simon's Bay for the southern crnise at 

 6.30 a.m. As the vessel steamed out to the open sea considerable differences in the 

 temperature of the surface water were observed. In Simon's Bay it was 64°"5 but at 

 10 a.m., when the Cape of Good Hope bore W. by K, distant 5 miles, it had fallen to 55°-5 

 and was accompanied by a corresponding decrease in the temperature of the air, which 

 ieli 3 -8. At noon, when Cape Hangklip bore N. 78° E., and Zwart Kop N 14° E the 

 surface temperature had again risen to 65°- , and there was also a rise in the temperature 

 of the air. At 1.30 p.m. a sounding and dredging in 98 fathoms, and serial tempera- 

 tures at every 10 fathoms, were obtained. The dredging was veiy successful. The 

 deposit consisted of a green glauconitic sand, containing 50 per cent, of carbonate of 

 lime, which was composed chiefly of Foraminifera, fragments of Molluscs, Polyzoa 

 Serpula;, and Echmoderms. At 6 p.m. sail was again made and a course shaped to the 

 southward. r 



On the 18th, at 6 a.m., sails were furled, and the ship sounded and dredged in 150 

 fathoms, and at 8.30 a.m. again made all sail to the southward towards Marion Island 

 The deposit was nearly the same as on the preceding day. Glauconite is exceptionally' 

 abundant in these deposits on the Agulhas Bank ; the grains are about one millimetre in 

 diameter, and are isolated or agglomerated into phosphatic nodules several centimetres 

 in diameter. Besides these grains, the Foraminifera are often filled with a pale areen 

 glaucomtic substance, which only rarely shows all the typical characters of glauco°nite 

 In these deposits there was much green-coloured amorphous matter, which, when heated 

 on platinum, burned like an organic substance, became black, then red, and gave off an 

 organic smell. & 



On the 19th, at 1 a.m., the temperature of the surface water rose from 65° to 72° 

 and remained at from 72° to 73° all day. At 6 a.m. a sounding and dredging were' 

 obtained in 1900 fathoms, as well as serial temperatures and specimens of the water 

 from several depths (see Sheet 18). The deposit was a Globigerina ooze, containing 90 

 Per cent of carbonate of lime, which consisted almost entirely of pelagic Foraminifera 

 In the dredge were several irregular brown-coloured phosphatic nodules, containing 49 

 per cent, of tricalcic phosphate. Whilst sounding and dredging, the current was found 



(XARR. CHALL. EXP. — VOL I. — 1884 ) 



/ 37 



