SHARKS' TEETH AND CETACEAN BONES. 183 



and calcareous oozes they were not observed." Furthermore, Mammalian 

 remains brought up from the sea-floor are for the most part limited to bones 

 of extremely dense structure, such as the ear-bones and- fragments of the 

 beaks of Ziphioid whales, the preservation of which is to be " accounted for 

 by the great density of these portions of the skeleton, and the consequent 

 small amount of surface presented to the action of the sea-water when 

 compared with the cancellated bones." l 



To our mind, the failure of the " Albatross " to bring up Cetacean remains 

 at Station 173 is devoid of special significance, and does not affect the 

 question of general distribution. More likely is the absence of such remains 

 at this point, in close proximity to the Paumotus, to be explained as the 

 result of local conditions affecting the solvent power of the sea-water. 



The discovery of Cetacean bones by the " Albatross " at Station 2 in 

 latitude 28° 23' N., and also at Station 13 in north latitude of about 10°, 

 is interesting, since no remains of this nature had been previously found 

 north of the equator, in either the Atlantic or the Pacific. With the excep- 

 tion of two fragments, all the bones of Cetaceans procured by the " Chal- 

 lenger" Expedition were dredged from red clays and Radiolarian oozes, 

 and " these were all situated in the central South Pacific, excepting Station 

 160, 2,600 fathoms, in the southern Indian Ocean, 500 miles southwest of 

 Australia." 



The general facts of distribution of sharks' teeth as observed by the 

 " Challenger " Expedition are thus stated by Dr. Murray : 2 " The distribution 

 of the sharks' teeth in the deposits is similar to that of the bones of Ceta- 

 ceans, although they were dredged more frequently. They are most 

 abundant in the red clay areas far removed from land, and especially in those 

 of the central South Pacific; they were less frequently taken in the organic 

 oozes of the deep sea, and only in one or two instances in the terrigenous 

 deposits surrounding continental or other land. It seems undoubted that 

 many of the teeth of sharks and the bones of the Ziphioid whales belong 

 to Tertiary and extinct species." 



To facilitate comparison, and to show at a glance the distribution, the 

 following table has been prepared, which shows the position, depth, and 



l -'Loc. at., p. 276. 2 Loc. cit., p. 270. 



