264 W. AND G- S. WEST 



them were actually collected by being thawed out of the ice, in which they could be 

 seen embedded. Others were obtained from under the ice of the lakes, and from the 

 lake- bottom, by digging through a great thickness of ice, in one case as much as 15 feet. 

 Yet others were exposed on the surface of the ice as the latter was removed by ablation 

 during the blizzards. 



The smaller ponds completely thawed in the brief summer period, but they did 

 not contain so many Algae as the more or less frozen lakes. 



It is evident from the foregoing remarks that the Antarctic Freshwater Algae have 

 a very severe struggle for existence, and evidences of this can be seen in many ways. 

 Both slowness of growth and interrupted growth are noticeable in the Prasiolas, and 

 the frustules of the more delicate diatoms, such as Tropidoneis Icevissima, exhibit 

 considerable deformity. 



The Algae observed in the collections were as follows : 



Genera Species 



Chlorophyceae ..... 6 . . 16 



Bacillarieae ..... 16 .. 30 



Myxophyceae 11 . . 39 



33 84 



Thus the Chlorophyceae were but feebly represented, and it should be remarked 

 that no Conjugatae were observed. The Myxophyceae (or Blue-green Algae) were the 

 most frequent, although the diatoms were very numerous in some of the lakes. Many 

 representatives of both these groups were mixed up in the sediment of the ponds and 

 lakes, and on the surface of the latter, often embedded in the ice, were very extensive 

 sheets of Myxophycese. These sheets were often of a brilliant blue-green colour, but 

 were frequently bleached, owing most probably to the intensity" of the light, and 

 were usually of a warm brown colour. 



There was a conspicuous absence of red or yellow snow in the region visited by 

 the expedition. A small amount of yellow snow was observed by Mr. R. E. Priestley, 

 of the Western Geological Party, but the collection was lost with much of the rest of 

 the impedimenta on that memorable escape of the members of this party from a 

 drifting ice-floe. 



Special attention is directed to the great salinity of the water of Green Lake, from 

 which locality quite a large percentage of the species recorded in this paper were 

 obtained. These species, which included a number of Algae generally regarded as 

 freshwater types, were certainly living in water in which there was a much greater 

 degree of concentration of salts than in ordinary sea- water. A number of typical 

 maiine diatoms occurred in this lake, but other species which were here plentiful 

 also occurred in other lakes and ponds in which the water was not strongly saline. We 

 have not, however, as yet any information as to the degree of salinity of Green Lake 

 in summer, when the ice is all melted. 



