138 E. HERON-ALLEN AND A. EARLAND ON SOME FORAM1NIFERA. 



submit for their consideration the examination of selected stations 

 along lines drawn east and west, in the manner of sections. A 

 large proportion of these in all probability could be dealt with 

 in a very summary manner, but the remainder might yield 

 results of importance as to the relation of distribution to salinity, 

 depth, temperature and current, possibly even affording evidence 

 of the main trend of the currents, which would provide a welcome 

 check on other observations carried out by current-meters and 

 drift -bottles. 



In regard to the samples which they have examined from 

 the deep water east of the Dogger it may be remarked that the 

 Admiralty tide charts show but low rates of velocity in the 

 district, which has moreover a greater depth of water than one 

 would expect to be consistent with frequent wave action at the 

 bottom. Recent current measurements carried out by the 

 Board of Agriculture and Fisheries have also failed to detect 

 any marked resultant current. It may therefore be suggested 

 that the sub-polish attained by the rounded grains is not in 

 all cases due to attrition on the spot. The freedom of the 

 adjacent Dogger Bank from silt, a grade of material found in 

 high percentage on either side, may perhaps be explained by 

 the finer particles churned up and held in suspension by wave 

 action during storms being gradually washed into the deeper 

 water : some segregation of the rounder grains may take place 

 in the same manner. A thorough geological examination of 

 the area, especially of the Scottish coast, might also show to 

 what extent, if any, the grains result from the disintegration 

 of certain definite sandstone rocks. 



For the action of wave and current in the Southern Bight 

 (North Sea south of 53) the collection of samples as a whole 

 furnish good evidence ; the material is to a great extent graded 

 as in a levigator, the average diameter of the sand particles 

 diminishing as the speed of the current declines. Yet even in 

 this district, with its shallower waters and far more powerful 

 currents, the upper limit of size of the particles affected is soon 

 reached, and one feels in consequence the need of searching for 

 other causes before explaining the rotundity of certain of the 

 grains near the Dogger by tidal action alone. J. O. Borley.] 



r . , . _____ _ , _, 



jQurn. Quefcett Mkyo-icopical CliLib, Ser. 2, YoLX.IL, Np. 73, November ]>Z3, 



