394 P. T. CLEVB, DUST FROM DRIFT-ICE AT JAN MAYEN. 



The sample 176 contained also a small number of in- 

 dividuals: 



Fresh water forms: Brackish or märine: 



Diatomella Balfoureana Grev. Calonceis cemula A. S. 

 Ennotiaprceriqjta V. curia GnvN. Clicetoc.eros sp. {spore.). 

 Pinnularia parva Greg. C. diadema Ehe. (spore.). 



CoscinodisGus lacustris Grün. 



Navicula imperfecta Cl. 



N. kryopliila Cl. 



N. suhinflata GrüN. 



A^. transitans Cl. 



Nitzschia gelida Grun. 



There were, besides, found some spores of flagellates. 

 The samples 174 and 175 contained foUowing forras: ') 



A. Plankton- forms: 

 Chcetoceros dehilis Cl. Spores c. 

 C. diadema Ehe. Spores cc. 

 C. fiircellatus Bail. Spores r. 

 C. mitra Bail. Spores r. 

 C. socialis Lauder. Spores rr. 

 C. teres Cl. Spores r. 

 C. sp. f. 



CoscinodisGus excentricus Ehb. 

 C. lacustris var. hyperhorea GrüN. cc. 



v. var. septentrionalis Grun. cc. 

 C. oculus iridis Ehe. r. 

 C. polyacanthus Grun. c. 



var. intermedia GrüN. + 

 Thalassiosira gravida Cl. Spores = Coscinodiscus suhglo- 

 hosits c. 



T. Nordeyiskiöldii Cl. cc. 

 Spores of flagellates c. 



') The letters r and rr- deuote rare and verv rare, c, cc, ccc common to very 

 common, the sign + not rare. 



