on board H.M.S. f Challenger' 



489 



Sounding 153. 8th September, 1873. 2050 fathoms. Lat. 7° 28' S., 

 long. 34° 2' W. A red or yellow mud containing : — Much amorphous 

 clayey matter of a red colour ; many coarse and fine mineral parti- 

 cles, chiefly quartz and mica ; a good many pelagic Foraminifera j 

 Coccoliths and Ehabdoliths ; a few siliceous spicules, but no Eadio- 



laria observed. 















fathoms. 



O 1 



o / 



adm 



gl54. 



8th Sept., 



1873. 1650. 



Lat. 7 39 S., long. 34 12 W. 



55 



155. 



9th 



675. 



„ 8 37 S., , 



, 34 28 W. 



55 



156. 



9th 



500. 



3 , 8 28 S., , 



, 34 31W. 



55 



157. 



10th 



350. 



,5 9 5 S., , 



, 34 50 W. 



55 



A. 



10th 



120. 



„ 9 10 S., , 



, 34 52 W. 



55 



B. 



10th 



32. 



,5 9 9S., , 



, 34 53 W. 



55 



C. 



10th 



400. 



„ 9 10 S., , 



, 34 49 W. 



55 



158. 



11th 



1715. 



„ 10 9 S., , 



, 35 11 W. 



55 



159. 



11th 



1600. 



„ 10 11 S., , 



, 35 22 W. 



55 



160. 



12th 



1200. 



„ 10 46 S., , 



, 36 2W. 



55 



161. 



12th 



700. 



„ 10 45 8., , 



, 36 9J W. 



55 



162. 



13th 



1015. 



5, 11 42 S„ , 



, 37 3¥. 



55 



163. 



14th 



1275. 



„ 13 6 S., , 



, 38 7W. 



All these soundings along the coast of South America, from Cape San 

 Eoque to Bahia, gave a red or yellow mud as described under soundings 

 152 and 153. Those in the shallower depths were of a redder colour 

 and contained larger mineral particles and fewer pelagic organisms than 

 those in deeper water and further from the coast. Eemains of siliceous 

 organisms were almost entirely absent. In No. 157 a, 120 fathoms, there 

 were a few red-coloured internal casts of Forarninifera. 



Bahia to Cajpe of Good Hope. 



Sounding 164. 30th September, 1873. 2150 fathoms. Lat. 20° 13' S., 

 long. 35° 19' W. A red mud containing : — Much amorphous clayey 

 matter ; many fine mineral particles, mica, quartz, &c. ; many 

 pelagic Foraminifera ; Coccoliths and Ehabdoliths ; a few manganese 

 grains ; no siliceous things noticed. 



Sounding 165. 3rd October, 1873. 2350 fathoms. Lat. 26° 15' S., long. 

 32° 56' W. A red Or grey clay containing : — Much amorphous 

 clayey matter ; a few rather large and many very small white mineral 

 particles ; a good many remains of pelagic Foraminifera; a few Coc- 

 coliths and Ehabdoliths ; a few small manganese pellets. 



Sounding 166. 6th October, 1873. 2275 fathoms. Lat. 29° 35' S., 

 long. 28° 9' W. A grey clay containing : — Much amorphous clayey 

 matter and some amorphous calcareous matter ; a few rather large 

 and many very small mineral particles, quartz, pumice, &c. ; a good 



