270 



с. H. OSTKNFKI.D. 



Grunow (1. с.) gives the size to 60//, I have found it ranging from 

 50 til 80 1Л. 



In the samples from Danmarks Havn in October 1906 I found 



Fig. 7. Auxospore of 



Coscinodiscus Joergen- 



senii n. nom. 



Fig. 6. (Coscinodiscus Joergensenii n. nom. Г)00 t. m. 



two specimens just coming from the auxospores and having one valve 

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

 kept; 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. Probatjly arctic neritic species, known from Cape Wankarema 

 ((irunow) 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 tlie limits of the species 

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

 Ьале a Ьаррл' 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 Bih. K. Svenska Vet, Akad. Handl., 

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

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



Di strib. Northern-temperate, oceanic species, known from the North- 

 Atlantic and the Antarctic. 



