PEELIMIXARY REPORT. 71 



of cetaceans more or less coated with manganese. There were a number 

 of species of sharks represented : Charchaordon, Lamna, Oxyrhina, Car- 

 charias. There were also a number of flat slabs coated with manganese, the 

 majority from three to four inches thick, but many were nearly six inches 

 through. We must have brought up at least 800 pounds' weight of nodules. 

 The slabs seemed to be composed of volcanic ash. There were many 

 rounded masses of pumice covered by manganese and fragments of the stem 

 of a Gorgonian (Isis) coated with manganese. 



At this Station we obtained 116 sharks' teeth, a few ear-bones and 

 other bones of whales and dolphins. 



jSTote. — Sir John Murray informs me that at Station 2 some of the material which 

 seemed to be manganese nodules proved to be rocks, evidently of continental origin, cov- 

 ered with a thia,coating of manganese. 



Mr. J. J. H. Teall, of the Geological Survey of England, who examined these rocks, 

 reports that they are a fragment of a rounded pebble, consisting of a typical hornblende 

 andesite ; a subangular fragment of a pale-green serpentine ; an angular fragment of a fine- 

 grained sandstone composed of grains of quartz, felspar, and epidote, minute grains of 

 mica being also present; fragments of a well-rounded pebble of black chert, traversed by 

 microscopic quartz veins. 



How these pebbles, having all the characteristics of glacial-worn pebbles, came to be 

 carried to this point is an interesting question. As the shark's-teeth and cetacean bones 

 found in the red clay seem to indicate that since tertiary times there have been but very 

 insignificant deposits at great distance from continental areas, similarly we may be 

 tempted to assume that these pebbles, which could not have been transported to their 

 present locality by any agency of the present epoch, were carried to it during the glacial 

 epoch, the thin coating of manganese indicating how small have been the bottom deposits 

 since the glacial period. 



The '•Challenger" obtained two bushels of manganese nodules at Sta- 

 tion 281, south of Tahiti, hit. 22' 21' S., long. 150 17' W., in 2385 fiithoms, 

 with centres of volcanic tufa and larger slabs covered at the surface and 

 in the cracks. The rounded masses of piunice probably have been carried 

 out to sea for a long distance and finally sinking became coated with 

 manganese on falling in the red clay deposit. This locality of the "Chal- 

 lenger" is only about 300 miles from our Station 173, where we also 

 obtained a magnificent haul of red clay and manganese nodules and 

 sharks' teeth. 



