8 



green Algae were especially mentioned , amongst others a new species Spirulina 

 subsalsa. 



0rsted's dissertation published three years later, in which the distribution 

 of the marine Algje in the Sound is discussed, is of greater importance. In this 

 paper, which deals with the geographical, geological, botanical and zoological con- 

 ditions of the Sound, all the species of Algae are mentioned, which were found there 

 by the author, but the single species are not described in detail, which is the rea- 

 son why it is not always possible to know the meaning of a name given by the 

 author. A number of species, considered by him as new, are however described 

 in the comments under the text, but mostly so briefly and incompletely, that the 

 plant cannot be recognised; and the result has been, that none of the genera and 

 species, given by 0rsted , have been maintained. Some of them have later been 

 published in Flora Danica. The systematic value of the paper in thus very small, 

 but its importance for our subject lies in this that it is based upon systematic 

 investigations by means of dredgings, with the result, that for the first time the 

 Algae are not only discussed in regard to their horizontal distribution but also 

 in regard to their vertical. It cannot be determined what new species have been 

 added to the flora by 0rsted's work without examining his specimens. 



Already several years before the appearance of 0usted's work, Lyngbye in 

 1830 had written a treatise of a somewhat kindred character, but, on account of 

 special conditions, it was not published before 1880". In floristic regard it is not 

 of so much importance in enriching the flora, as in its being based upon investi- 

 gations in the southernmost part of the Kattegat off Gilleleje, a region not investi- 

 gated before, and especially by its containing more exact data on the distribution 

 of the Algae in relation to the depth. Neither his nor 0rsted's divisions into re- 

 gions of depth need be mentioned here. 



Since Orsted's work there has not until the end of the 19th century appea- 

 red any noteworthy, floristic or systematic contribution to the Danish literature 

 on the Danish marine Algae. In Flora Danica marine Algae from Denmark were 

 included up to 1861, but very few new species were added beyond those mentioned 

 by LiEBMAN and 0rsted. Helminthocladia purpurea '', found by Miss Caroline 

 Rosenberg, is perhaps the most interesting addition. During the same period pub- 

 lications which partly deal with the algal flora in Danish territory have appeared 



^ A. S. 0RSIED, De reoionibus uiarinis, elementa topographiae, liistoriconaturalis freti 0resund. 

 Hauniie 184-t. 



' H. C Lyngbye, Rarioi a Codaiia lOpusculi posthumi pars). Vidensk. Meddelelser fra den naturli. 

 Foren. i Kjobeiihavn, 1879—80, p. 215. 



^ In "Nomenclator Florae Danicae' published by Joh. Lange in 1881 a systematic summary, pre- 

 pared by myself, was given of all the Algae mentioned in this work with data on their occurrence. 

 This general summary, whicli in regard to the determination of the species, is essentially based upon 

 the references available in the literature and consequently in part out of date, comprises the following 

 Danish marine Algic: 47 Rhodopycew , of whicli two are however incorrectly named as Danish, 38 

 PhceophycecB (1 incorrectly named Danish), 18 Chlorophycece and 7 Cyanophycew. By accident the Cha- 

 raceae were omitted in this work. 



