FRESHWATER ALOJ5. 



In its habitat D. Antarctica resemlilcs D. mii'-iculu F. Hustedt (Hedwigia, XLVIII., 



pp. 140-141), which also gro\v,s in the mucilage of a AW/*-, lint Hustedt's species is a 

 much larger form with curved cells, having marked attenuated'apices. The Antaivtie 

 form is much nearer to D. inoiitmia W. and G. S. West ; the cells of this species arc 

 however appreciably larger, are more pronouncedly spindle-shaped, and the species is 

 not endophytic, The cells in />. iih>nt<ni<t also appear to be more regularly arranged 

 than in D. antarctica (</. G. S. West, Brit. Freshw. Algae (1904), p. 348, fig. 1G2A). 

 A form like D. antarctica approaches very near to an J/</>"//^//-< . 







Genus GLCEOCAPSA Kiitz. 

 21. GLCEOCAPSA RUPICOLA. 



(ili'ocujitu, i-itfiii-nla Kiitz., Spec. Alg. (1849), p. 221 ; Eubenborst, Fl. Europ. Alg., ii. (1*G.~>), p. I;!. 



Diam. cell. = 4-5 /j. ; diam. colon, usque ad 30 p. 



Ilali. Gap pond, Winter Harbour, December loth, l'J03 (on surface of 

 Phormidium) ; freshwater pond, Granite Harbour, January 20th, 1902 (in sediment). 



The small colonies were spherical or elliptical. The inner sheaths were deep 

 red-brown, often almost completely obscuring the cells. A closely allied species 

 (<t. shuttleworthiana Kiitz.) is recorded by Messrs. West (oj>. cif., p. 29G). 



Genus ArnAXoxHECK Nageli. 

 22. APHANOTHECE PRASIXA. 



Aphanothece prasinn A. Bnuin in Ikibcnk. Alg. Nu. l.")72 ; Rabenhorst, Fl. Enrop. Alg., ii. (18C5), 

 pp. G5-GG. 



ILili. Ice-wall, five feet above present level of river-like pond, "Penknife ice," 

 McMurdo Strait, September 13th, 1902. 



Small, but otherwise typical colonies, attached to /'//<</////>///// ,/lnc/nlt'. This 

 species is generally free-floating. 



Genus MICROCVSTIS Jviitxing. 



23. iMU'ROCYSTIS CHROOCOCCOIDKA. 



(PI. II., figs. 102, 103.) 

 JUicrocyslis chroococcoidea AV. and (J. S. West, oj>. ri/., p. L",)(;, I'l. XXVI., iigs. 107-1 1 1. 



Diam. cell. = 4 fj.. 



llnli. Gap pond, Winter Harbour, December 15th, 1903. 



Occasional colonies of this interesting form were found on the Pkorinidium-sheetB 

 from the above-mentioned locality. They agreed well with the description published 

 by Messrs. We?.t, except that the cell-contents appeared homogeneous. 



VOL. VI. K 



