THE VOYAGE OE H.M.S. CHALLENGER. 
806 
On the 14th October, from 2375 fathoms, there were again over two bushels of 
manganese nodules, the great majority of which were in form like marbles, from one- 
fourth of an inch to one inch in diameter. The nuclei of the nodules were either frag- 
ments of sharks’ teeth or fragments of bones, of palagonite, pumice, or other volcanic 
fragments. Fifteen hundred specimens of Sharks’ teeth were counted from this haul, 
and in addition to these there were great numbers of small teeth and their fragments 
in the washings of the trawl and in the substance of the nodules themselves. In all these 
teeth the hard enamel-like dentine alone remained, the vaso-dentine and osteo-dentine 
having been removed and their place occupied by depositions of the oxides of manganese 
and iron mixed with clay. There were also forty-two petrous and tympanic bones, 
determined by Professor Turner as belonging to Balcenoptera, Balcena, Megaptera, 
Mesoplodon, Delpliinus, and Globiocephalus, together with ten or twelve fragments of 
bones without any definite shape, but apparently belonging to Cetaceans. 1 
On the 16th October, in 2335 fathoms, there was over a bushel of manganese 
nodules, Sharks’ teeth, and bones of Cetaceans. Three hundred and forty Sharks’ teeth, 
over half an inch in length, were counted, some of the largest Carcharodon teeth from 
this haul being over three inches in length. There 
were about ninety tympanic bullae, and in addition 
to these many fragments, coated by, and imbedded in , 
peroxide of manganese ; forty-two detached petrous 
bones were also obtained. Forty-two specimens also 
occurred which consisted not only of the petrous, but 
of a portion of the elongated mastoid element con- 
tinuous with it. There were also two portions of 
beaks of a Zipliioid Whale, one being over eight 
inches in length. A number of fragments of flat 
bones, most of which were portions of the brain-case, 
though one or two might have been bits of the shaft of 
a rib, occurred. An irregular mass of spongy bone, 
4 by 8 by 3 inches, consisted apparently of a portion of the expanded wing of a superior 
maxilla. There were also present many undeterminable fragments of bone, all apparently 
belonging to Cetaceans. 
On the 23rd October, in 2550 fathoms, there was again a large haul of manganese 
nodules with nuclei of palagonite, Sharks’ teeth, and earbones of Whales. Of three large 
tympanic bones obtained here, one was 4 inches, another 3^ inches, and the third 3 
inches in length. These were all thickly covered with nodulated depositions of peroxide 
of manganese ; sufficient of this was removed to show that they were all bullae of Whales 
of the genus Balcenoptera. A large number of the nodules had bony nuclei, but the 
1 Zool. Ghall. Exp., part iv. p. 40, 1880, 
Fig. 292. — Petrous and tympanic bone of Ziplvius 
cavirostris. 16tb October 1875 ; 2335 fathoms. 
