■'•ii^ 1)iatomacb:a<; — rhizosolenia 



(trU)hi'i-: T);]- N. 31"' W., rare. 

 Xori'iiilwr: 51° N. 1,-^- W., rare. 



Temperature: ll.o, mean of 31 obs., max. 2H.7, min. o.. 

 Salinity: 3.').s9, mean of 29 obs,, max. 35.89, min. .34.»2.* 

 Plankton-type. Noted from the Mediterranean, the Indian and 

 Pacilic Ocean. It follows in the Atlantic the African coast to the 

 Azores and spreads in the spring towards the English Channel. It 

 reached in May 60° N. and Scotland, in August S. Iceland, in Sep- 

 tember N. Iceland. From S. Iceland it crossed Denmark's Sound for 

 K. Greenland. It occurred also in the western Atlantic, but was 

 there much rarer. — .s. 



RHIZOSOLENIA ARAFURENSIS Castr. 



(H. Peragallo: Le Diatomiste 1892 PI. XV fig. 6.) 



Marrli: io^ N. 36° W., rare. 



Temperature: «. 



Salinity: 35.65. 



Plankton-type. Found in the Arafura Sea. — 1) '? N y. 



RHIZOSOLENIA ATLANTICA Peragallo.' 

 Le Diatomiste 1892 PI. XVII fig. 4—5.) 



1898 March: 42° N. 42° W. to 41° N. 49° W. 



XoiX'inber: 24° N. 29- \V., common; 51° N. 2(/ W.; 42- N. 



64° W. 

 Dcreiiibcr: 18° N. 67 -^ W. 



1899 Fcbniarii : 34° N. 40° W. 



Temperature: 11 to 22.9, exceptionally 26..s. 

 Salinity: 35 to 36.3.i. 

 Plankton-type: s'. 



' Only such samples in which this species occurred in some atjuiidaiice 

 Imvi: heon considered in calculating the means. 



