126 ''■ I^o'oi 't' I' HoSICNVINGi:. 



A IVagnuMil ol" an Acrosiplionid which secnis lo hcloiij^ lo lliis 

 species has been nul wilh. riie filamenls are 154 — 175// Ihick and 

 are partly composed of ralher short cells, only twice as long as 

 broad. They are nuich like A. hystrix f. dcbilis (K. Rosenv.), only a 

 little thinner (comp. Jonsson 1. c. p. 48). 



I^oc. Damnarks ihivn. 



A. sp. 



Some of Ihe samples contain fragments of another species of 

 Acrosiphonia in small (piantities. They occur together with several 

 loose algæ and have undoubtedly also been loose. Owing to their 

 small quantity and their incomplete and sterile condition they are 

 scarcely determinable. The filaments are 50— 90 /^ thick; hooked 

 branches do nol occur. A complete specimen, possibly belonging 

 to the same species, was met wilh on a stone dredged at Cape Bis- 

 marck Peninsula. Us filaments were up to 121a thick. The cells 

 were in this specimen, as well as in the loose ones, several times 

 as long as broad, and rhizoidal branches were abundant. The last- 

 named specimen was also sterile. 



I^oc. East Side of Koldewey Island; alonj^ Cape Bismarck Peninsula; 

 bay ofT Vesterdalen. 



Chætoniorpha Kütz. 



48. Ch. Melagonium (Web. et Mohr) Kütz. 



K. Rosenvinge (1893) p. 917, (1898 I) p. 104; Jonsson (1904) p. 51. 



Most of the specimens in the collection seem to have been loose. 

 Some of these specimens are very vigorous, about 1 mm. in diameter 



and consist of cells which are one 

 to two diameters long, while others 

 are much thinner, from 100// up to 

 300// in diameter, and composed of 

 cells which are 3 to 4 diameters 

 long. As there is so great a break 

 between these two forms, one might 

 Fig.S. ChœtomorphaMelagoniumf.tenuis^^ inclined to think that they re- 

 Upper end of a cell, showing nuclei, n, present two different species, but 



pyrenoids, p, and stroma starch. 200 : 1. t^g specimens being on the whole 



rather scarce in the collection, and 

 the species being very variable in breadth also in other arctic 

 regions (comp. K. Rosenvinge 1898 p. 104), I judge it preferable to 

 consider the thin filaments as an extremely thin form of the same 

 species. It might be named f. tenuis. The thinnest specimens ap- 

 proach in breadth to the thickest filaments of Chœtomorpha tortuosa; 

 they differ however in having much more numerous nuclei, viz. 



