‘270 
THE VOYAGE OF H.M.S. CHALLENGER. 
many hundred fragments and teeth of small size. The majority of the teeth were more 
or less thickly coated with manganese, the smaller ones apparently to a greater extent 
tlian the larger ones. The hard dentine of one of the Carcharodon teeth was found to 
contain 33 ‘66 per cent, of phosphoric acid, equal to 73 '48 per cent, of tricalcic phosphate, 
and 2 "28 per cent, of fluorine. The inside of the tooth was filled with deposits of man- 
ganese, iron, and clayey materials, resembling the manganese nodules in composition, 
and containing only 0 83 per cent, of phosphoric acid. 
Station 286, 2335 fathoms. — Over 350 sharks’ teeth and fragments were counted 
from this station, including about thirty Carclmrodons^ half of them perfect, the largest 
nearly 3 inches (76 mm.) in length; about two hundred Oxyrhina Lamna teeth,^ 
the largest of the former 2^ inches (64 mm.), and of the latter If inches (44'4 mm.), in 
length ; and over one hundred small teeth, Hemipristis, &c.® All the teeth were more 
or less deeply imbedded in depositions of manganese. Three of the Oxyrhina teeth 
yielded 32'58 per cent, of phosphoric acid, equivalent to 71 T2 per cent, of tricalcic 
phosphate, while the black material which filled the interior of the teeth yielded only 
7 ‘97 per cent, of phosphoric acid, equivalent to 17’39 per cent, of tricalcic phosphate. 
Station 289, 2550 fathoms. — One perfect Oxyrhina tooth., about inches (28'6 mm.) 
in length, deeply imbedded, and fragment of a similar tooth. 
Station 293, 2025 fathoms. — One Carcharodon tooth, about If inches (44'4 mm.) in 
length, and one Oxyrhina tooth, about If inches (31 ‘6 mm.) in length, the former with, 
the latter without, a coating of manganese. 
Mammalia. — The remains of Mammalia were exceedingly rare in the great 
majority of the Challenger’s dredgings and trawlings. In all the terrigenous deposits 
and calcareous oozes they were not observed, but the “ Blake ” expedition dredged oflf the 
coast of North America a few bones, and one or two sharks’ teeth belonging to the same 
species as some of those noted in the foregoing list. Numerous remains of Cetaceans 
were collected by the Challenger in the same trawlings in which the sharks’ teeth were 
obtained, principally the dense earbones and beaks of Ziphioid whales, but besides these 
were a few fragments of the other more areolar bones, evidently in the process of being 
dissolved by the action of the sea-water. A microscopic examination of the nuclei of 
the manganese nodules revealed the fact that many of these concretions had been formed 
around bone fragments, the structure of which had almost disappeared. The following 
list gives the number, condition, and nature of these Mammalian remains in the trawlings 
and dredgings at the several stations where they were procured — 
* SectionH of one are given in PI. X. figs. 4, 4a. 
* 8ce PI. VI. figs. 14, 22 ; PI. X. fig. 5 (section). 
* See PI. V. figs. 8, 9. 
* All these lx>nes were examined and determined by Professor Sir William Turner ; see Report ou the Cetacea, 
Zool. Cball. Exp., |^>ort iv. 
