EEPOET ON THE DEEP-SEA DEPOSITS. 
179 
up the principal part of the deposit ; these had been present in many of the previous 
deposits, but never in such abundance as in this instance. There was no carbonate of 
lime, and Radiolaria, which had been so abundant in previous deposits in this section, were 
only represented by a few specimens. The same remark as to the absence of Radiolaria 
applies to the next two stations, where the depths were 2350 and 2325 fathoms respec- 
tively, but there was in these 28 and 9 per cent, of carbonate of lime, which was due to 
the presence of calcareous Foraminifera. The deposit in 1525 fathoms was a Volcanic 
Mud containing 20 per cent, of carbonate of lime (see Chart 38 and Diagram 19). 
In every instance the dredgings and trawlings yielded some manganese nodules and 
pumice, but on two or three occasions the manganese nodules were in extraordinary 
abundance. From 2750 fathoms on the 11th September there was over a peck of heavy, 
very compact, oval-shaped nodules. The largest were 10 centimetres in width and 5 
centimetres in depth ; the upper surface was smooth, while the under one was rough and 
irregular. Although differing in size, most of these nodules had the same shape, indeed 
it may be remarked that there is generally a close resemblance both in composition and 
shape and sometimes in size among the nodules from any single dredging. Among the 
nodules were sixteen sharks’ teeth of considerable size, two being those of Carcharodon, 
nine Oxyrhina, and five Lamna; some of these were deeply imbedded in deposits of 
manganese. There were in addition to the above eight earbones of Cetaceans belonging 
to the genera Globiocephalus, Mesoplodon, and species of Delphinidae. 
On the 16th September, from 2350 fathoms, the trawl brought up more than half a 
ton of manganese nodules, which filled two small casks. The great majority of these 
nodules were small and nearly round, resembling a lot of marbles with a mean diameter 
of three quarters of an inch. The nuclei of these nodules were generally palagonite or 
other volcanic material, but very frequently small sharks’ teeth or fragments of bone. 
Among the nodules were counted two hundred and fifty sharks’ teeth, without taking 
into account those less than half an inch in length. Three of the teeth belonged to 
Carcharodon, being from 2 to 2^ inches (5 to 6 ‘3 centimetres) across at the base of the 
dentine. Ten resembled those of Carcharias, and the remainder were referred to the 
genera Lamna and Oxyrhina. The Cetacean bones among the nodules consisted of two 
tympano-periotic bones of Mesoplodon, eight separate petrous bones, and six tympanic 
buUse belonging to Globiocephalus, Dclphinus, and Kogia (?). 
Off Tahiti. — So irregular was the ground from the reef out to 35 fathoms that 
dredging was almost, if not quite, impossible; still by means of the swabs and tangles 
some Corals were obtained. From 35 to 40 fathoms down to 150 fathoms dredging 
was equally difficult. Here a number of Sponges, Alcyonarians, Corals, and other 
invertebrates were obtained. Beyond 150 fathoms the bottom was a Coral Sand with 
volcanic minerals and pelagic shells. The soundings taken by the ship at depths of 420, 
590, 620, and 680 fathoms showed the presence of a Volcanic Mud, containing from 19 
