FRESHWATER ALGA. 5 
C. subcaudata Wille) and Chloromonas alpina Wille, are, however, as yet only 
known to occur in the Antarctic and in the north of Europe, although it is 
hardly likely that future investigation will fail to reveal their occurrence in 
intermediate regions. 
Another interesting case of distribution is that of species like Chloromonas 
alpina Wille, and the genus Fwucapsis, which have hitherto only been recorded 
from alpine habitats. Parallel cases have long been known in the Arctic regions. 
The collections of the ‘Discovery’ did not include any material of snow floras. 
On- the other hand, two samples (Cape Adare, January 9th, 1902; McMurdo Bay, 
September 13th, 1902) came from the ice. It will be useful to give a list of the 
commoner species found in these two habitats :-— 
CapE ADARE (in freshwater ice under boulder). McMurpo Bay (dull brick coloured ice). 
2a SA | icrocystis parasitica Kiitz. var. glacialis yar 
Chloromonas alpina Wille. | TS: NETS ER SRN UE HS 
| 
+ parasitica Kitz. 
ie merismopedioides F. EK. Fritsch. 
Bucapsis minuta sp. 0. |  Phormidium frigidum sp. n. 
| *Pleurococcus antartius W. and G. 8. West. 
= issectus Niig. 
Navicula muticopsis Van Heurck. Nase ati - = 
| *WMelosira sp. (cf. p. 46). 
2 cymatopleura W. and G. S. West. Fragilaria tenuicollis Heib. var. antartica W. and 
| G. 8. West. 
| Navieula seminulum Gran. 
3 seminulwn Grun. - muticopsis Van Heurck. 
es cymatopleurus W. and G. S. West. 
Se. , is es shackletoni W. and G. S. West. 
Surirella angusta Kiitz. - globiceps Greg. 
The colour of the ice in the second case was due to Microcystis parasitica 
Kiitz. var. glacialis nov. var. The species marked with an asterisk did not grow 
directly on the ice, but were epiphytes on the Phormidium. 
As above mentioned, the bulk of the material collected by the members of 
the British National Antarctic Expedition consisted of Phormidium-sheets with their 
abundant epiphytic flora. The general character of this flora is sufficiently illustrated 
by the Table on p. 4. Only a few samples comprised free-floating forms, the more 
important of which were as follows :— 
Chlamydomonas subcaudata Wille. Oscillatoria tenuis Ag. and other species. 
33 intermedia Chod. Nostoc disciforme sp. 0. 
95 ehrenbergi Gorosch. »  longstaffi sp. n. 
Hormidium stage and young packets of 5 fuscescens sp. 0. 
Prasiola-cells. 5 Sspheericum Vauch. 
Penium sp. (¢f. pp. 20, 21). Nodularia quadrata sp. 0. 
Microcystis marginata (Menegh.) Kiitz. Navicula muticopsis Van Heurck. 
Merismopedia tenuissina Lemm. 4 globiceps Greg. 
Hucapsis minuta sp. n. . shackletoni W. and G. S. West. 
Phormidium antarcticum W. and G.S. West. — | »  cymatopleurus W. and G. 8. West. 
