264 С. H. Ostenfeld. 



In the samples from 1906 this species was only found twice and 



in very few specimens; also in 1907, in the samples from Danmarks 



Havn it was rare. In 1908, on the other hand, it was common in 



many of the samples on the whole way from Danmarks Havn through 



the pack-ice. In several samples the cells were very small, so-called 



hunger-specimens. The resting spores (Coscinod. subglobosus) were 



present in two samples (Septm. 1907, July 1908). July —August — 



September. 



Distrib. Northern neritic species widely distributed along the coast 

 bordering the Arctic and North Atlantic Oceans and their tributaries. 



6. Thalassiosira bioculata (Grun.) Ostenfeld, Bot. of the Færoes, 

 vol.2, 1903, Copenhagen, p. 564, figs. 120-121; Gran, Nord. Plankton 

 XIX, p. 19, fig. 14; Coscinodiscus b. Grunow, Dial. v. Franz Josefs Land, 

 1884, p. 30 et 56, pi. С, fig. 30, pi. D, figs. 1-2. 



Single individuals were found in several of the samples from 

 Danmarks Havn, the coast water and also in the pack-ice. Chains 

 are not seen and the species was not found in stage of strong growth. 

 July — August — September. 



Distrib. Northern neritic species known from the coast regions of the 

 northern countries bordering the Davis Strait, northern Atlantic and Arctic 

 Oceans. 



Bacterosira Gran, 1900. 



7. Bacterosira fragilis Gran, Nyt Mag. Naturvid., Christiania, 

 38, 1900, p. 114; Nord. Plankton, 1905, XIX, p. 21; Lauder ia f. Gran, 

 Bibliotheca botanica. Heft 42, 1897, p. 18, pi. 1, figs. 12—14. 



Found very sparingly in samples from Danmarks Havn and the 



coast-water, not in the pack-ice. July — August. 



Distrib. Arctic neritic species known from the coasts of the arctic 

 Sea West- and East-(ireenland, Spitsbergen, Nova Zembla) and from the 

 northern coast of Norway. 



Lauderia Cleve, 1873. 



8. Lauderia glacialis (Grun.) Gran, Nyt Magaz. Naturvid., Chri- 

 stiania, Bd. 38, 1900, p. Ill, pi. 9, figs. 10—14; Nord. Plankton, XIX, 

 p. 23; Podosira hormoides, var. glacialis Grunow, Diat. Franz Josefs 

 Land, 1884, p. 56, pi. C, fig. 32; P. glacialis Cleve, Bill. K. Svenska 

 Vet. Akad. Handl., Bd. 22, afd. 3, No. 4, 1896, p. 12, pi. 2, figs. 17-20; 

 Porosira g. Jørgensen, Bergens Museums Skrifter, 1905, p. 97, pi. 6, 

 fig. 7. 



Rare in the samples, found in Danmarks Havn and in the coast 



water, not in the pack-ice. July — August. 



Distrib. Northern (sut^arctic) species known from the coastal regions 

 of the arctic Sea and along the coasts of North-Europe (in winter). 



