THE CATEGORIES OF LIFE 



9 



deposit at depths of about 500 to 1500 fathoms is 

 that known as Pteropod ooze. This consists to a 

 ilarge extent of the shells of the pelagic mollusca 

 - .rAP\vn as Pteropoda. We should not encounter any 

 patches of this ooze in our traverse across the North 



Diatom ooze 



Pteropod ooze 



Radiolarian ooze Globigerina ooze 



Fig. 1. Deep-Sea Deposits. 



Atlantic where the greater part of the sea-bottom, 

 outside the limit of distribution of the terrigenous 

 muds, consists of Globigerina ooze. This is a soft 

 white or grey mud containing gritty particles and 

 composed largely of carbonate of lime. The picture 



