430 



DEPTHS OF THE OCEAN 



Station 4, 923 metres (547 fathoms). Besides 332 fishes, quantities of star- 

 fish, sea-urchins {Brissopsis, Fhormoso?na), etc. 



South of the Faroe Islands, 831 metres (460 fathoms). Besides 300 fishes, 

 large numbers of invertebrates. 



In Chapter IV. Sir John Murray has stated that the bottom- 

 samples collected during the cruise of the " Michael Sars " show- 

 that Globigerinaooze approaches nearer to the coasts of the British 

 Islands than was previously supposed, having been found at 

 Station 4, 547 fathoms; Station 93, 688 fathoms; Station 95, 

 981 fathoms; Station 98, 742 fathoms; and Station 100, 835 

 fathoms. 



While the fishes of the continental shelf all live on terrigenous 

 deposits, like Blue mud, the " MichaeliSars " results prove that 

 in the eastern Atlantic, at any rate, most of the fauna of the 

 continental slope live on Globigerina ooze. Circumstances may 

 be quite different on other slopes, as, for instance, the Atlantic 

 slope off the United States, or off Newfoundland, where terri- 

 genous deposits seem to have a much wider distribution. But 

 the very important question of the limits between the terrigenous 

 and the pelagic deposits requires further careful study by means 

 of series of hauls with the trawl and series of samples of the 

 deposits from shallow water down the slope to the abyssal plain. 



The results given above show in any case that . the 

 Globigerina ooze in depths of 550 to 1000 fathoms may be a 

 rich ground for animal life, since we got such good hauls at 

 the stations quoted, and this is corroborated by the hauls taken 

 on this type of deposit in deeper water, far from continental 

 land, as at Stations 53 and 88. 



At Station 53, south of the Azores, 2615 to 2865 metres 

 (1430 to 1570 fathoms), the trawl captured in one haul, besides 

 39 fishes, about 500 holothurians, and abundance of different 

 crustaceans, actinians, etc. 



At Station 88, in 3120 metres (about 1700 fathoms), the 

 trawl brought up a wealth of animals, especially sea-urchins, 

 starfish, ophiurids, holothurians, etc. 



We thus see that it is not terrigenous deposits alone wJiich 

 harbour an abundant bottom fauna ; in fact, on true pelagic 

 deposits, like Globigerina ooze, we may have the conditions 

 necessary for abundant life. The percentage of carbonate of 

 lime gives no indication of the suitability of the conditions for 

 animal life, for the terrigenous deposits with abundant fauna, as 

 well as the barren Red clay, both contain very little calcium 

 carbonate. The important item is the organic stcbstance con- 



