38 THE DEPTH AND MAEINE DEPOSITS OF THE PACIFIC OCEAN. 



rather exceptional circumstances, the deposit itself being a Globigerina Ooze 

 forming at a very moderate depth (1142 fathoms). In Station 297 of the 

 " Challenger," where there is also a Globigerina Ooze, the manganese nod- 

 ules present are perfect nodules, and there is, moreover, a great abundance 

 of palagonitic tuff, not met with in the case of this formation. 



Phosphatic Concretion. 



At Station 4642 (lat. 1° 30.5' S. ; long. 89° 35' W. ; depth, 300 fathoms ; 

 7th November, 1904), the trawl brought up an irregularly-shaped phosphatic 

 concretion, four inches long, reddish-brown, very hard, and of high specific 

 gravity. A fresh fracture shows it to be composed of numerous shells of 

 Foraminifera, cemented by a reddish-brown matrix of amorphous phosphate 

 of lime. The carbonate of calcium amounts to 36.36 per cent, the remain- 

 ing portion being composed of phosphate of lime, with a little iron oxide 

 (2 or 3 per cent at most), and insoluble residue. The latter is formed of 

 mineral particles represented principally by plagioclase and augite. No 

 glauconite is present. The surface is slaggy-looking, vacuolar, and rough to 

 the touch ; the only places where it has a shining appearance are inside the 

 larger vacuolce. The nature of the surface is the same everywhere, and 

 organisms are growing on it in different places, so that the nodule could 

 not have been embedded to any great extent in the deposit. 



Sharks' Teeth and Cetacean Bones. 



The remains of whales and sharks brought up from the floor of the 

 Pacific during this cruise of the " Albatross " were submitted to Dr. C. K.. 

 Eastman, who had previously reported ^ on the similar remains procured by 

 Dr. Alexander Agassiz on his earlier cruise in 1899-1900, and the following 

 notes on the teeth and tympanic bones dredged at the various stations are 

 taken from Dr. Eastman's report : ^ — 



"Station 4656, depth 2222 fathoms. There were brought up by the 

 dredge from the bottom at this station 10 sharks' teeth, amongst which 4 

 are recognizable as belonging to the genus Lamna, 1 to Oxyrhina, 1 to Car- 

 charodon, this last being a fine specimen, and the rest merely fragments. 

 The cetacean material consisted of 1 tympanic bulla of Hyperoodon, 1 peri- 



1 Mem. Mus. Comp. ZooL, Vol. XXVI., p. 179, 1903. 

 = Btdl. Mus. Comp. ZooL, Vol. L., pp. 80-82, 1906. 



