366 E. M. KINDLE 



permanent routes in the sea bottom. Many of these probably 

 move the finer sediments toward and over the border of- the con- 

 tinental shelf as definitely as terrestrial streams move their sedi- 

 ments toward the sea. 



Geologists and paleontologists may learn much regarding the 

 role of marine currents from the keen analysis of living faunas 

 which such investigators as Peterson are making. This author 

 who has discriminated and mapped several sharply contrasted 

 bottom faunas in the Skagerrak and Kattegat finds that 



The Modiola epifauna occurs especially where there is a strong current 

 close to the bottom, clearing away the finer particles so that stones and shells 

 lie exposed, affording sites for attachment for the Modiola, which may here 

 occur in such numbers as entirely to cover the bottom (see PL IX) for great 

 tracts in the current channels.' 



The inferences which we can at present make concerning some 

 of the conditions controlling marine sedimentation are based on 

 such detached bits of evidence as have been brought together 

 in this paper. It is hoped, however, that it will soon be possible 

 to base conclusion relating to such problems on intensive studies of 

 numerous selected areas of sea bottom in which areal mapping of 

 bottom deposits will be an important feature. 



' C. G. Job. Peterson, "The Sea Bottom and Its Production of Fish Food," 

 Rcpt. Danish Biol. Sta. to Board of Agricidture (1918), p. 15. 



