I] 



THE CATEGORIES OF LIFE 



deposit at depths of about 500 to 1500 fathoms is 

 that known as Pteropod ooze. This consists to a 

 large extent of the shells of the pelagic mollusca 

 known 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 



