PLAXKTOX DIATOMS IX ST. ANDREWS WATERS 



TABLE IX. 

 Bathymetric Range. Station 3. July 31. 



57 



These show a distinct maximum at 10 metres, and then a rapid decrease. Below 

 20 metres the decrease is gradual and somewhat irregular until at 150 metres few 

 diatoms are found. At the bottom, however, a decided increase will be noted due to 

 an abundance of Melosira sulcata. The latter is the only form which is found to 

 increase with descent. 



Records similar to the above were made for Station 6 on July 27 and August 15 

 and are listed in Tables X and XI. 



TABLE X. 

 Bathymetric Range. Station 6. July 27. 



In the former a maximum was obtained at 22 metres, below which a marked 

 decrease was evident. In the latter we find an exception to results previously recorded 

 for the surface waters were found to contain a distinct maximum, chiefly due to the 

 great abundance of Sl-eletonema costatum and Chaetoceras sociale, forms of extreme 

 delicacy. 



