INTRODUCTION. 
Earlier sources of our knowledge of Denmark’s marine Algæ. 
W hen on searching for the oldest statements in the literature on the Danish 
marine Alge, we come upon ÖEDER’s Enumeratio plantarum Flore Danice', we 
might expect to find important information there, as the work deals specially 
with the “Cryptanthere” i. e. the cryptogams. A considerable number of species 
of the genera Conferva, Ulva and Fucus are certainly mentioned there, but these 
are not known to occur inside the boundaries of the Danish kingdom. As the - 
author, according to his own statement, had not studied the lower plants very 
closely, he contents himself with giving a good many North-European species, 
which he supposes might be found here. This paper therefore does not contain 
any more information about the Danish marine Algz than that found in “Flora 
Danica”, to which work reference is made for all the species figured there. OEDER 
has certainly mentioned not a small number of species in this monumental pictor- 
ial work, which began to appear in 1761, but they are almost all from Norway 
and Iceland or without indication of the locality. Only two species are noted from 
Denmark, namely Tab. 166, Fucus siliquosus (1763) [Halidrys siliquosus (L.) Lgb.] and 
Tab. 393, Fucus fastigiatus (1768) [Furcellaria fastigiata (Huds.) Lamx.]. 
In the parts of the same work edited by O. Fr. Mürrer (1775—1782) only 
a few marine Alge from Denmark were mentioned (Tab. 763, Ulva prolifera | Entero- 
morpha prolifera (Müll.) J. Ag.]; Tab. 771, 2, Conferva Linum |Chelomorpha Linum 
(Müll.) Kütz.]; Tab. 821, Fucus Filum [Chorda Filum (L.) Stackh.]; Tab. 882 Conferva 
flexuosa [Cladophora sp.|; Tab. 889, Ulva Linza |Enteromorpha Linza (L.) J. Ag.]), 
and none at all in the parts edited by Martin Var. At the end of the 18th 
century information was thus present about only a very small number of species 
of marine Algæ found on the coasts of Denmark. 
In 1803 ScHuMACHER® gives 26 species of Algæ from the coast of Sealand. 
A considerable proportion of these are however so insufficiently described that 
1G. €. OEDER, Enumeratio plantarum Flore Danicæ. Cryptantheræ. Hafniæ 1770. 
? Icones Flore Danicæ. Hafniæ 1761—1883 (Edit.: Orper, ©. F. MÜLLER, M. VAHL, HORNEMANN, 
LIEBMAN, JOH. LANGE). 
3) C. F. SCHUMACHER, Enumeratio plantarum in partibus Sællandiæ septentrionalis et orientalis. 
Pars posterior, Hafniz 1803. 
