316 



Ovi. I'aii.skn. 



Tilis species ol" which fig. 

 IC) gives some oulline-ligures, 

 was very com mon in Aug. 190S 

 in the sea outside the ice. In 

 the pack-ice and the coastal 

 water in IIIO.S it was scarce 

 though found in several samples. 

 In Danmarks Havn and in Uie 

 pack-ice and the coastal water 

 in 1906—07 it was rare and 

 occurred always as dead spe- 

 cimens. 



Dislrib. Arclie oceanic spe- 



I'ia. 16. Ceratiuni arclicum, dilTerent cells. i)4 t. m. 



Apodiniiiin Challon. 



26. Apodiniuni (?) Chaetoceratis n. sp. 



Cellulae globosae nucleiferae niembrana cellulosoidea tectae, ad 

 setas Chaetoceratis horealis appendicula adharentes et memhranam ejus 

 perforantes: parasitiis igitiir phisina hospitis exhaiiriens. Divisionihus 

 cellulae binae et quaternae nascuntur. Long. cell. ca. 13—25 «. Hah. 

 in mare gelido ad oram orientalcin Groenlandiae. 



Dr. Ostenfeld who has worked out the Diatoms and Flagel- 

 lates of the present samples hefore I got them for investigation, 

 called my attention to this organism which he had examined be- 

 lieving it was a Diatom. But as the wall gave cellulose-reaction 

 "with chloriodide of zinc and as it was without silicium he saw^ it 

 would be nearer a Dinoflagellate than a Diatom, and he gave me 

 his drawings and notes. 



Once only I have found a cell of Apodinium Chaetoceratis upon 

 an awn of Chaetoceras decipiens, all other specimens seeiî were 

 fixed on the awns of Ch. boréale. Whether this is because the 

 awns of Ch. boréale are set with fine hairs I cannot tell wùth cer- 

 tainty, I have never seen the cells spit upon the hairs or otherwise 

 fixed to them. But it seeins likely that awns set with setae afford 

 better chance for fastening than smooth ones. How the cell is fixed 

 to the awn is difficult to discern. Fig. 17, C and D show a little 

 process by aid of which the cell is fixed. In other cases it seems 

 that there are two processes. Fig. F shows a cell made pellucid 

 by aid of Eau de Javelle, and on both sides of the awn is seen a 

 thickening not belonging to the awn but to the Apodinium. Fig. I 

 <drawed by Ostenfeld) shows two cells in a mucilage which is 



