DIATOMACE^ — RHIZOSOLEXIA Mi\ 



Hcpteiirhcr: 62° N. 1° E., very comftion; 65" N. 1° W., very 

 common (deep sea haul from 100 — m., maximum at 50 

 m.) 66" — 67° N. 2° — 3" W., not common or rare. 



Temperature: 14. i, mean of 16 obs., max. 21.4, min. 5.8 

 (only such observations considered as relate to samples containing 

 this form abundantly). 



Salinity: 34.78, mean of 14 obs., max. 36.25, min. 30,62. 



Plankton-type. I have found this form in samples from the 

 Red Sea. It occurs more or less sparingly in the Equatorial, An- 

 tilles and Florida Currents. Its principal area of distribution is the 

 area between the Azores, the west coast of Europe and the Faroe 

 Channel. I never found it abundantly in the North Sea, but in the 

 Skagerak and along the Scandinavian coast it occurs during the 

 summer in great abundance. As it occurred in September 1899 very 

 abundantly in the deeper water-layers at 62^ — 65° N. 1° E. — 1° 

 W^ there is reason to believe that it arrives into the Skagerak 

 through the »Norske Rende». It seems thus to follow the 200 metre 

 plateau round the French and British coasts. In some years it pro- 

 cedes so far as off Beeren Island, where it was found abundantly 

 in September 1896. — Nid, S. 



RHIZOSOLENIA GRACILIS H. 1. Smith?i 

 (Peragallo: Le Diatomiste 1892 PI. XVI fig. 17.) 

 1898 August and Novi'mbcr: Azores, abundant. 



Temperature: 18..^. 



RHIZOSOLENIA HEBETATA Bail. 

 (Peragallo: le Diatomiste 1892 PI. XVIl fig. 10). 



1898 March: 61° N. 5° W. 

 April: 50° N. 10° W. 



Seems to be a dwarf-form of li. ffvtiijera. 



