General Remarks. 
With regard to algae, South Africa — as well as all the rest of 
this continent — is rather incompletely known. The most momen- 
tous contributions to our present knowledge of the freshwater 
algae here are of comparatively recent date, viz. FrITSCH, Å First 
Report on the Freshwater Algae, mostly from the Cape Peninsula 
(Annals of the South African Museum, Vol. IX, 1918). As the author 
here mentions the few earlier works treating of the algal vege- 
tation of South Africa, I need in the present case only refer to this 
treatise.') All these earlier works, however, only deal with the 
freshwater algae, the true subaérial algae being totally left out of 
consideration, and thus the subaérial algae of this continent have 
been absolutely unknown till now. Our knowledge of the subaérial 
algae of the southern hemisphere is, on the whole, extremely scanty, 
and excepting one family only, the Trentepohliaceae — which has 
been examined by various investigators as SCHMIDLE, KARSTEN, 
DE WILDEMAN, and some others — our knowledge of the 
subaérial algae 'of the southern hemisphere is very sparse and 
accidental. 
Under these circumstances it was with particular interest I 
undertook the examination of quite a considerable collection of sub- 
aérial algae in the possession of the Botanical Museum of Kristiania. 
This collection — 403 samples in all — chiefly consisted of pieces of 
bark, samples of wood, and the like, collected for the Botanical 
Museum by Ørsan OLsen, lecturer on zoology at the University 
of Kristiania, during a sojourn in South Africa in the years 1912— 
1913. The collection was made party in the environs of Durban, 
on the east coast, in the period Oct. 24th—Nov. 17th,1912, partly on 
the west coast, in the environs of Saldanha Bay, in the 
period March 10th—19th, 1913. 
Å list of the samples follows below: 
No. 1—10. Close by the shore, at the South African 
Whaling Company's station, Bluff, Dur- 
ban rinddense wood Oct. 24th, 1912 
1) While this paper was being printed, FrirscH together with Miss 
E. SrepHEns published åa new contribution to our knowledge of the 
freshwater algae of Africa: Freshwater Algae (exclusive of Diatoms), 
mainly from the Transkei Territories, Cape Colony. (Transactions of 
the Royal Society of South Africa, Vol. IX, Cape Town 1921). I mention 
the above work in this way for the sake of completeness. 
