270 



(". H. Osi KM 11,1). 



(iiiiNOW (1. C.) givc>s the size lo 60 /i, I have found il rnnginf.; from 

 50 til 80 11. 



In Ihe samples from Danmarks Havn in Oclober 1906 I found 



Fig. 7. Auxospore of 



Coscinodiscus Joergen- 



senii n. nom. 



Fig. 6. Coscinodiscus Joergensenii n. nom. ÖOO t. m. 



Iwo specimens just coming from the auxospores and having one valve 

 developed while the other half of the cell had the perizoniiim wall 

 kepi; and in the same samples I also found some globular bodies 

 of just the same size and with the same con- 

 tents of chromatophores, etc. ; these globules I 

 consider as the auxospores of this species. In 

 the figures 7 I have given such a globule and 

 the auxospore-cell at the same magnification. 

 As the cells seem to live solitary, the mature 

 auxospore — as in C. suhbuliens — does not 

 occur adherent to its mother-cell. 



Di strib. Probably arctic neritic species, known from Cape Wankarema 

 (Grunow) and Arctic Norway (Jørgensen). 



Note. It has been said many times before, but I cannot help repeating that 

 the genus Coscinodiscus is in a great confusion and that the limits of the species 

 are very indistinct. It is to be hoped that a monographer will be found who may 

 have a happy hand to clear up this difficult matter. 



Asteromphalus Ehrbg., 1844. 

 15. Asteromphalus Hookeri Ehrbg., Monatsber. Berlin. Akad. 

 Wissensch., 1844, p. 200, fig. 3; Gran, Nord. Plankton, 1905, XIX, p. 45, 

 fig. 50; A. Brookei Bail., var., Cleve Bib. K. Svenska Vet. Akad. Handl., 

 Bd, 1, 1873, p. 10, pi. 4, fig. 19; A. atlanticus Cleve, Bib. K. Svenska 

 Vet. Akad. Handl, Bd. 22, afd. 3, No. 4, 1896, p. 5; K. Svenska Vet. 

 Akad. Handl. Bd. 34, No. 1, 1900, p. 19, pi. 8, figs. 7—9. 



A single specimen was met with in a sample from the outer 



part of the pack-ice; August 1906. 



Distrib. Northern-temperate, oceanic species, known from the North- 

 Atlantic and the Antarctic. 



