268 
THE VOYAGE OF H.M.S. CHALLENGER. 
the other fisli bones are largely made up of phosphate of lime associated with much 
albuminoid matter. The otoliths of a cod gave on analysis — 
Lime (CaO), ..... 53'08 
Carbonic Acid (CO.,), .... 43‘85 
Magnesia (MgO), . . . . 2'7l 
Phosphoric Acid (PgOg), . . . trace 
Alumina (AlgOg), .... 0:22 
Silica (SiOg), 0‘33 
♦ 
10019 
Tlie teeth of fish are rather rare in terrigenous deposits and tolerably abundant in 
some pelagic deposits ; in certain regions of the Central Pacific and in the other oceans 
in great depths far removed from land, the teeth of sharks were most exceptionally 
abundant in many of the deeper trawlings and dredgings. These sharks’ teeth, it will 
be observed, are from red clay areas as a rule, it being the exception to find any of 
the large sjiecimens in the calcareous oozes or terrigenous deposits. In general all that 
remains is the hard dentine or enamel, the whole of the vaso-dentine having disap- 
peared. In this respect the condition of these teeth diflFers from that of those belonging 
to the same species from the Tertiary deposits in Malta, Carolina, Australia, and from 
one tooth dredged by Agassiz from the existing sea-bed in relatively shallow water ofi’ 
the coast of North America in all these the vaso-dentine and the base are almost 
always preserved. In the following list details are given as to the number, size, and 
condition of the teeth procured by the Challenger Expedition in the trawlings and 
dredgings in the order of the stations — 
Atlantic Ocean. 
Station 16, 2435 fathoms. — Two Oxyrhina teeth, the larger inches (38 mm.) in 
length ; one Lamna, about an inch (25*4 mm.) in length. 
Station 106, 1850 fathoms. — One Lamna tooth, 1| inches (68 mm.) in length. 
Southern Indian Ocean. 
Station 160, 2600 fathoms. — Two Carcharoclon teeth, one broken, over 1^ inches 
(38 mm.) in length, and three small Lamna teeth. 
Pacific Ocean. 
Station 237, 1875 fathoms. — Two vertebra) and several large otoliths of fish. 
Station 241, 2300 fathoms. — One small Lamna tooth, a little over half an inch 
(127 mm.) in length. 
• Ma^Ie by J. O. Rosh. ’ See AgasHiz, Three Cruises of the Blake" voL i. p. 276, 1888. 
* Dr. AlWrt Gunther of the British Museum examined these teeth and was satisfied that the determinations were, 
as far as possible, correct. 
