26() H. с. Ostenfeld. 



1905, p. 33, flg. 33; Ostenfeld, Wiss. Ergebn. Aral-See Exped.. VIII, 

 St. Petersburg, 1908, p. 149, pl. 7, figs. 4-5. 



In a sample from the outer part of the pack-ice a single dead 

 frustuce of this species was found. August 190(5. 



Distrib. Widely distributed oceanic species, according to Grax com- 

 mon, especialh' during winter, in the Gulf-Stream area of the Norwegian 

 Sea and in tlie North Atlantic; not at home in arctic water. 



11. Coscinodiscus subbuliens Jørgensen, Bergens Museums 

 Skrifter 1905, p. 94, pl.VI, fig. 2: Gran, Nord. Plankton XIX, 1905, p. 32, 

 fig. 32; C. oculus iridis Gran, Fauna Arctica, III, Lief. 3, 1904, p. 519, 

 pl.XVII, figs. 17—19. 



The species which I refer to Jørgensen's С. subbuliens is very 

 common in some of the samples from the autumn, indeed forming 

 the main part of the phytoplankton. 



Owing to the abundance of material I have been able to add 

 some points to the descriptions given by Jørgensen and Gran. As 

 to the size of the species Jørgensen gives a diameter of "usually 

 50 — 100«", and Gran says 65— 150 /y, while my measurements extend 

 it to 240;/ (185« as mean of 20 measurements) for the normal vege- 

 tative cells. The valves are coarsely areolated in a radiate manner, 

 and in contradistinction to the descriptions of the two quoted au- 

 thors I have found that, at a certain adjustment, a single row of 

 very small points or apiculi are discernible a little inside the margin 

 and further, asymmetrically among them, two larger apiculi or knots, 

 at a distance from one another of between 12(P and 150'. The 

 apiculi which are difficult to see, best upon ignified material moun- 

 ted in styrax-balsam, stand rather closely, as between two usually 

 3 — 4 radii of aréoles originate. The existence of the two larger 

 apiculi shows that C. subbuliens must be referred to the Group Bia- 

 piculaii created by me in 1908 (Wiss. Ergebn. d. Aralsee-Exp., Lief. 

 VIII, St. Petersburg, 1908, p. 147). Further investigations must decide, 

 if all species of the sectio Radiati Rattr. possess these two apiculi; 

 hitherto they have been found in C. biconicus Van Breem., С aralensis 

 Ostf., C. Granii Gough, C. centralis Ehrbg. and C. concinuns W. 



Gran (1904, fig. 19) has figured the construction of the girdle of a 

 specimen which just has divided into two daughter-cells and where 

 the matter is more complicated than in the ordinary cells. Therefore 

 I have given a figure (Fig. 2) showing the girdle of a normal cell'. 

 This figure represents only a part of the girdle, but it is seen di- 

 stinctly, that in the connecting part of each valve two structure-lines 



1 The fig. 32 с iiî Gp.an's paper of 190.") is not quite clear in this respect. 



