9 
in the neighbouring countries. Bornholm’s algal flora has thus been investigated, in 
connection with that of the inner Baltic, by Krok! who gave valuable information 
regarding this region, not investigated until then. During the years 1870—1875 two 
expeditions were made from Kiel respectively to the Baltic and to the North Sea, 
on which occasions some dredgings were also made in the Danish waters, mostly 
in the Great Bell, and reports on these have been given by P. MaGnus”. By these 
dredgings the existence of Algæ at great depths was determined in the Great Belt, 
among which were some species not found before in the Danish waters (Antitham- 
mion Plumula, Chylocladia clavellosa (Lomentaria clavellosa), some Lithothamion-species 
and the new species Callithamnion (Rhodochorton) membranaceum Magn.). 
The marine Algæ have not in general been included in the Danish local floræ, 
or only the most obvious mentioned en passant; in J. P. JAcoBSEN’s list of the 
plants? found in Læsø and Anholt only some few species of marine Algæ from 
each of these islands have also been mentioned. Corrın’s work on the marine 
fauna" of the Limfjord contains some remarks about the flora of this fjord, in 
which some of the most important species in the composition of the flora are 
mentioned, partly from the information given by J. P. JacoBsen. The number of 
the species stated is however also here too small to be of any importance in flo- 
ristic regard. One of the species mentioned, Rhodomenia mamillosa (Gigartina ma- 
millosa (Good. et Woodw.) J. Ag.) is however of interest, as it had not previously 
been found on the coasts of Denmark. 
For two smaller groups however we find special contributions in the literature. 
The Characee, which in this country have not usually been studied in connection 
with the other Algæ, were included in two editions af LANGE's manual’ and were 
later exhaustively studied by P. NIELSEN, especially in South West Sealand". In 
1880 I published a preliminary report on the submarine Vaucheria-species, the 
number of the known Danish species being thereby augmented‘. 
Collections employed for the present work. 
My work is naturally mostly based upon my own collections, but it need 
hardly be said that I have also employed all the marine Algæ accessible to me 
1 Th. ©. B. N. Krox, Algfloran i inre Östersjön och Bottniska viken. Öfversigt af K. Vet. Akad. 
Förhandl. 1869. 
? P. MAGNUS, Botanische Untersuchungen der Pommerania-Expedition vom 3. bis 24. August. Aus 
dem Bericht über die Expedition.... Pommerania. Kiel 1873. 
P. Macnus, Die botanischen Ergebnisse der Nordseefahrt vom 21. Juli bis 9. Septbr. 1872. Il. 
Jahresber. der Kommission z. Unters. d. deutsch. Meere in Kiel. Berlin 1874. 
3 J. P. JACOBSEN, Fortegnelse over de paa Læsø og Anholt i 1870 fundne Planter. Botan. Tids- 
skrift. 11. Bind 1879. 
‘ Jonas Corrın, Om Limfjordens marine Fauna. Kjøbenhavn 1884. 
> Jon. LANGE, Haandbog i den danske Flora. 2. edition 1859, 3. edition 1864. 
% P. NIELSEN, Exsiccatsamling af Characeer, navnlig fra Danmark. 1869. Idem, Sydvestsjællands 
Vegetation. Botanisk Tidsskrift 2. R. 2. Bd. 1873. 
7 Botanisk Tidsskrift Bd. 12, p. 11. 
D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 1. 
rm 
