F. E. FEITSCH. 



TABLE SHOWING THE COMPOSITION OF THE EPIPHYTIC PLOEA ON THE CYANOPHYOEOUS 



SHEETS IN THREE ANTARCTIC PONDS. 



N. globiceps Greg., N. shackletoni W. and G. S. West, N. cymatopleurus W. and 

 G. S. West, N. borealis Kiitz.), Fragilarias (especially F. tenuicollis Heib. var. 

 antarctica W. and G. S. West) and Ilantzschias [H. amphioxys Grun., and H. elongata 

 Grun.), while tlie other genera appear to be more casual.* Diatoms were rather 

 scantily represented in my material, being common only in two of the samples ; in 

 many habitats they were exceedingly rare. 



In comparison with Arctic regions the scarcity of green Algge is very noticeable 

 (c/. W. and G. S. West, op. cit., p. 265). The publications of Nordstedtf and 

 others have shown that Desmids are relatively abundant in these regions. The 

 other green Algse are well represented, while the Cyanophycese are appreciably 

 less important. Some of the species of Chlamydomonas {C. caudata Wille,J and 



* Messrs. West also mention the abundant occurrence of Tropidoneis Icevissima W. and G. S. West, in some 

 of the lakes ; I have not met with this form. It should be remarked that abundant fragments of the valves of 

 diverse Centricse were observed in several samples, although intact specimens were rare. 



t Nordstedt, Desmid. ex ins. Spetsbergensibus et Beeren Eiland in expeditionibus ann. 1868 et 1870 suecanis 

 oollectsB. Ofvers. af Kgl. Vet.-Ak. Forhandl. (1872), Stockholm, No. 6, p. 23 ; Nordstedt, Desmidieee arctose, op. cit. 

 (1875), No. 6, p. 13. 



t Cf. F. E. Fritsch, op. cit., p. 322. 



