DIATOMACK/T'; — ( IH.F.TOCKROS i!<)9 



April: -M-" N. 15" W-, rare; 1H" N. il- W., rare; Faroes, com- 

 mon; Westmanno, common. 



Mail : as a rule rare from 61° N. 1° E. to the Shetlands and 

 the Faroes, where not rare; rare between the Faroes and 

 Iceland; common at Westmannao; 50° N. Hi)- W. and 1>< 

 N. 45^ W , rare; 47' N. oQ-' W., common. 



./«//('.■ Westmannao, common; 62' N. 1° K. to 67' N. 8' W., 

 very common; more or less rare round Jan Mayen; 71° N. 

 9° W. to 73' N. 4° W. as a rule rare; between Norway and 

 Beeren Island not rare; SW. and S. of Spitzbergen, rare. 



July: NW. of Spitzbergen, rare; 78 N. 53' E., rare; 75° N. 

 18' W to 71° N. 21° W., rare to common; 52 --53' N. 

 54°_51o AV., not rare. 



August: 80' N. 51° E. and 76' X. 41° K., rare; 70- 50' N. 

 22- 33' W., lonimon; 71°— 73- N. 20'— 27' W,, more or 

 less rare. 



Scpteiiibci-: 81° N. 16' E. to 73' N, 1<)- E., common to rare; 

 69- N. 13- W., rare; 53 N. 52' W., rare. 



Ocroln-r: 53' N. 31° W., rare. 



Temperature: 7.(i, mean of 17 obs.,' max. 13.5, min. O.d. 



Salinity: 34. .-,o, mean of 47 obs., max. 35.91, min. 30 gs. 



Plankton-type. I have found this species in a collection 

 from Puget's Sound. The mean temperature and salinity prove that 

 this species is an arctic form, which however spreads by currents 

 far to the south and propagates in water of so high a salinity as 

 35 J), m. — ('., T. ((' in 35 p. m. T. in 34 p. m. salinity.) 



ch.s:toceros densus Cl. 



(r. borciilis rar. dvn^. Cl. A Treatise on the Phyto-plankton PI. I fig. 3, 4.) 



1898 January: 12' N. 19' W.; 16' N. 18' W. (common). 



March: 25' N. Ki' W.; 49' N. 18' W.; 49' N, 2- W.; 45' N. 



36° and 40' W. (rare); 41' N. 49' W. 

 April 50° N. 3° W.; 47° N. 40' W. 



^ The means are calculated from such samples only as contained this species 

 abundantly. 



