BIHANG TILL K. SV. VET.-AKAD. HANDL. BAND 20. AFD. III. N:0 2. 11 



Dinopyxis Icevis Stein. 

 Diplopsalis lenticula Bergh. 

 Proroccntrum micans Ehb. 



The doiibtful Dictyochoe have been identified by tbe aid 

 of KtJTZiNG's Bacillarieen. As I have found the skeletons ouly 

 I am unable to decide whether they are radiolarias or flagel- 

 lates. 



Diatoms. Among the diatoms, named in the above lists, 

 many species are well known aiid may easily be found in the 

 Synopsis of Van Heurck, but there is a certain number of 

 forms, partly new, and partly described in not easily aeces- 

 sible papers, which want descriptions and figures. This is 

 especially the case with the species of Chcetoceros, which genus 

 greatly requires revision. This induces me to publish the 

 following notes and remarks on the Swedish species of this 

 genus. The interiör resting cells of Choefoceros, usually named 

 »spores , I describe as endocysts, as they are not formed by 

 conjugation as the auxospores are. 



CeratauUna Bergonii H. Per. (Monogr. du genre Rhizo- 

 solenia p. 7, Pl. I, f. 15, 16). — This species is extremely 

 hyaline and the annuli of the connecting zone are seen with 

 difficnlty. It was first described by me as Zygoceras? pelagi- 

 cum (Kanonbaaden Haucks Togter p. 54) but from dried and 

 misshapen specimens. Consequently, my description and tigure 

 leave much to desire and I prefer the name given by Peragallo, 

 wlio has acurately fignred it. — Pl. I, fig. 6. 



Chveioceros aflanticus Cl. (Diat. from the Arctic Sea p. 11, 

 Pl. II, f. 8). — Filaments moderately silicious, multicellular, 

 with broadly lanceolate foramina. Cellules quadrate, touching 

 each others at the angles and with concave interiör margins, 

 in the middle of which projects a small spine. Setee of the 

 filament and at the ends of almost ecjual strength, finely tran- 

 versely striate, with four rows of small aculei. The setai of 

 the upper valve are almost horizontal, those of the loAver valve 

 bent downwards. Terminal set» moderately divergent. — 

 (!ell-contents coccochromatic. — Breadth of the filament O, os 

 m. m. 



This species ocurred rarely in the Grullmarsfjord towards 

 the end of July 1893 at the depth of about 50 meters. The 

 cell-contents of a living specimen contained several rounded 

 chromatophores. 



