14 P. T. CLEVE, HYDROGRAFISKA UNDERSÖKNINGAR. 



dium V. Heurck Syn. Pl. LXXXII bis f. 1, 2 (all endocysts). 

 — C. protuherans Castr. Diat. of Challeuger Exp. p. 76, PL 

 VIII, f. 2? — C. mamiUanum Cl. Kanonbaaden Haucks- 

 Togter p. 55, 1889 (all filaments without endocysts)]. 



The endocysts of tbis species have long been known, and 

 iignred, as Ch. didymus and Ch. Gasiridium. They were very 

 abundant in November in plankton of Gullmarsfjord and were 

 enelosed in cellules of the filaments of the Chcetoceros, named 

 by me Ch. mamillanus. This name may tberefore yield to 

 the older name of Ehrenberg although that denotes the endo- 

 cysts only. — Chcetoceros didymus is a very characteristic 

 species, easily recognised by its cellules, having in the centre 

 of the valves a conical protnberance, as well as by the divergent 

 setae, and especially by the peculiar endocysts. — Pl. I, 

 fig. 3, 4. 



C. distans Cl. (D. of the Sea of Java p. 9, Pl. II, f. 11 

 a. b.). — Filaments rather thin and membranaceons, multi- 

 cellnlar, with large rectangular or qnadrate foramina. Cellules 

 nearly qnadrate, with concave interiör margins. Setse of the 

 filament delicate, bent downwards. Terminal setee moderately 

 divergent, strong, with shallow denticulations. — Pl. II, f. 2. 



In the original specimens from Java the setse of the 

 filament are stronger, but are otherwise similar. I have not 

 sncceeded in examining the cellules in S.V. for which reason 

 I do not know whether the setse are curved in the same direc- 

 tion or divergent 



C. Schiittii Cl. N. Sp. — Filaments moderately silicious, 

 multicellular, with small and narrow foramina. Cellules in 

 F. V. qnadrate. with slightly concave interiör margins, touching 

 each other at their angles; in S. V. narrow elliptical. Setae 

 of the filament rigid, at right angles to the filament. Termi- 

 nal setee coarser, diverging at a right angle, with a spiral of 

 small puncta — Cell-contents placochromatic. — Endocysts 

 with hemispheerical valves, spinous with short, numerous, not 

 branched bristles. — Breadth of the filament 0,oi2 m.m. — 

 Ch(pJ. sp. ind. Schutt Ueber d. Gattung Chsetoceros Pl. III, 

 f. 2, 3. — Pl. I, fig. 1. 



This species is characterized by its strongly divergent 

 terminal setse and by the setee of the filament, which are 

 directed at right angles to the axis of the filament, and are 

 not coherent at their base as is the case with Ch. decipiens. 



