REMARKS ON THE BOTTOM DEPOSITS. il 
recently of two series of deposit-samples, the one collected a quarter of a 
century ago by the U.S.S. “ Tuscarora,” the other collected in 1890 by the 
U.SS. “ Albatross,” and it bears striking evidence to the bipolar distribution 
of the pelagic Diatoms whose frustules fall to the bottom in such numbers 
as to form continuous bands of Diatom Ooze on the seaward borders of the 
Blue Mud areas both in the far south and, on a smaller scale, in the far 
north, 
