FRESHWATER AI/JJE. 



25 



It does not seem possible to distinguish adequately between Kiitzing's M'icroct/Ktis 

 and his Microhaloa firma (= JSficrocystisJirma). The colonies observed in 

 the present material really combine the characters of the two species. 



I'm'. GLAriAi.is var. nov. 



Cellulis minutissimis, dense aggregatis in familiis plerumquc ct saepe valde 

 irregularibus, in mueo rubiginoso invulutis : cuntontum cellularnm dilute a>rugincum 

 esse vcrisimile est. 



Diam. cell. = '5 p. ; diam. colon, usque ad 40 p.. 



Hah. Dull brick-coloured ice, situated in long level line as though in situation 

 of former water-level, four feet above frozen water-course through " Penknife " ice, 

 McMurdo Bay, September 13th, 1902. 



This form is partly, if not entirely, responsible for the colouration of the ice in this 

 habitat. The minute cells are densely aggregated in a brownish-red mucus, which 

 seems to be the only essential point of difference from the type. As far as could be 

 made out the cells themselves have pale blue-green contents. 



Genus MERISMOPEDIA Meyen. 



27. MERISMOPEDIA TEXUISSIMA. 



(PI. I., figs. 49-51.) 



Merismopedia tf/mitixinia Lemmermann, Beitr. z. Kenntn. d. Plunktonalgen, Rot. Oentralbl., Ixxvi. (1*98), 

 p. i:>4. 



Diam. cell. ca. 1*5 fj.. 



Ilnli. Damp spot, summit of Cape Adare, January 9th, 1902. 



The colonies were composed of small, generally closely placed cells, and consisted 

 of sixteen or frequently thirty-two or even sixty-four cells, forming verv regular 

 compact plates of small dimensions. The cell-contents were pale blue-given and 

 homogeneous. Wille (Antarkt, Algeu, Nyt -Mag. f. Naturvidenskab, xl. (1902), p. 219) 

 has recorded another form of this genus (J)/". glaucum (Ehrb.) Nag. var. i>nnct<itinn 

 (Meyen) Hansg.) from Cape Adare, but the cells in the colonies of my material were 

 too minute to belong to this species ; they differed also in their frequently den<e 

 aggregation. 



Genus EUCAPSIS Clements and Shautz. 



28. EUCAPSIS MINUTA sp. 11. 

 (PL I., figs. 47, 48.) 



Familiis s;epe irregularibus, scd e fasciculis cubicis 8-32-128 vcl plurium 

 cellularum compositis, libere natautibus, cum tegumento hyalino mucoso aivto ; cellulis 

 hemisphsericis vel subglobosis, geminatim dispositis ut in genere Cln-ouci>c<;>. 

 cytoplasmatc plcrumque dilute ;vrugineo (pnosertim in familiis novellis), sed interdiim 



K _' 











