820 DIATOMACE.K — C'.OSCIXODISCUS 



May: P'aroes, very common; 04" N. 12 W. to 61" N. 1" W., 



more or less rare; 48' N. 45' \V. to Mr N. 57" W.. 



common. 

 Juur: IV N. 9'— 10" W. and 69' N. la' W., rare; Westman- 



nao, rare; 62" N. 2"^ E., not rare; between (57' N. 11" E., 



70" N. 20^ E. and 71° N. 6° E., rare. 

 Jiilij: along the ea.'^t coast of (ireenland, between 71" and 



75" N.. usually rare, but in some spots common; 80" N. 



14" E.; 75" N. 49" E. to 79" N. 53" E., not rare; 56" N. 



38" W. to 52' N. 44" W., in some spots very common. 

 AiKjiist: along the east coast of Greenland, 71" — 73" N., rare; 



76" N. 41" E., rare; 80" N. 51" E., very common. 

 September: 77" N. 14" E. to 75" N. 17" E., rare. 

 (Mober: 56" N. 31" W., rare. 



Temperature: for the northern Atlantic 6.?, mean of 34 obs., 

 max. 19.8, miri. — 1..-,.' — North of South America 25, i to 26.7. 



Salinity: for (he northern Atlantic 34. 4o, mean of 35 obs., 

 max. 36.33, min. 30.y>s, exceptionally 26.,^. — North of South Ame- 

 rica 32..^2. 



Plankton-type. This species is a decided arctic species, 

 occurring most abundantly along the coasts and entering the Tricho- 

 plankton. Its occurrence north of S. America is therefore extremely 

 interesting, especially as I could not find any difference between the 

 tropical and arctic form. Occurs in Bering Sea. — T. Ns. Ng. 



COSCINODISCUS POLYCHORDUS Crax. 



(Don Norsko Nordliavs t'.xpedilion, 1H7(i-i<S7S, I'rotophyta pag. 'r>[) Pli. tl (ig. 33, 



PI. IV (ig. 06.1 



1898 Mareli: 58" N. 6" E. 

 May: 12' N. 16" \V. 

 July: S. of Iceland. 

 October: Eiiroes. 



1899 Aj)/'i/ andJ/r//y: Faroes. 



Only sucli samples considered as contained tiiis species abnndantU. 



