606 



beginning of May it is replaced by Phneocystis , which is, how- 

 ever, dominant in one gathering only; on the other hånd, in the 

 middle of May, a rich plankton consisting of Rhizosolenia obtusa 

 and Leptocylindrus appears; in the middle of June, the former dis- 

 appears and Chaetoceras decipiens and Nitzschia seriata (Chæto- and 

 Nitzschiaplankton) take its place, the latter, however, only for a 

 few days, as it is absent in July. Chaetoceras decipiens continues 

 to be common for a very long period, and not until September 

 does it give way for the temperate Rhizosoleniae (Soleniaplankton) 

 intermixed with Nitzschia deticatissima, which otherwise invariably 

 accompanies N. seriata. In October these neritic associations dis- 

 appear, and the waters of the ocean with its Disco- and Sphæra- 

 plankton fill the Sounds of the Færoes without being able to call 

 the other dormant associations to life, presumably on account of 

 the slight power and d uration of the light. Thus the year ends, 

 and in this way begins and goes on into January and February of 



1899, Table VII. But now a visitor occurs abundantly, which per- 

 haps may be regarded as neritic, viz. Coscinodiscus concinnus, and the 

 two oceanic species of Chaetoceras (Ch. atlanticum and Ch. decipiens). 

 In March we meet with the first indications of neritic life, viz. the 

 arctic-horeal Biddulphia anrita which occurs in the plankton in its early 

 spring-stage only. In April Biddulphia is joined by a great many other 

 forms, so that the plankton may more particularly be characterized 

 as Siraplankton, but with some of the indications of the next stage, 

 the Contorto-association ; the latter is predominant in the beginning 

 of May and continues to be so, though in a lesser degree, through- 

 out the whole of the month. Leptocylindrus and Rhizosolenia ohtnsa 

 which occurred abundantly in 1898 did not appear in May 1899, 

 and unfortunately the gatherings ceased at the end of the month, 

 so we do not know if they occurred at all ; the few oceanic samples 

 (Table III) give unfortunately no information as regards this question. 



After these gatherings — which were collected at the reqnest 

 of Prof. Cleve — were brought to an end, no samples were taken 

 until October 1901 when Dr. K. Poulsen l)egan his gatherings at 

 the request of the author. 



1901 , Table VIII. In the firsl sample only a few organisms 

 occur, which may indicate Scolicaplankton; but in the sample of 

 November 1. Chaetoceras debile and Rhizosolenia Shrubsolii constitule 

 the main part, i. e. Contorto- and Soleniaplankton; but this does not 

 appear lo lasl long, the sea taking its winter- repose in December 



