INTRODUCGTION 
Je a comparativety small number of species, belonging to the Gigarli- 
nales, Rhodymeniales, and Nemastomatales, are treated in the present part, seven years 
have been spent in completing it. This is partly due to the fact that some of 
the species offered problems that demanded thorough investigations. Two of these 
problems have been treated in particular papers, viz. (1) the question of the 
reproduction of Phyllophora Brodi@ei and the nature of Actinococcus subeulaneus'), 
and (2) the question of the reproduction of Ahnfeltia plicata*). 
In the years elapsed since the publication of the third part of this work, 
numerous gatherings have been made in several places on the coasts, and dredgings 
have been made in many new stations which are recorded below. Many new 
localities have been stated for species recorded in the foregoing parts, but these are 
not named here; only a few species belonging to the orders treated in the foregoing 
parts but not named there are mentioned here under Addenda. 
List of new Dredging Stations arranged according to the different Waters. 
Kattegat, Northern Part. (Kn) 
gR. 17/729. Midway between Hirsholm harbour and Kelpen. — 8 m. — Boulders (picked 
up). On the upper side mostly Halidrys siliqu., on the other sides many others, e. g. 
Deless. sangu., Polys. viol., Phylloph. membr., Codium toment., (young plants), Rhodym. 
palm., Bryopsis plum. and many others. 
gl. ‘/:28. Midway between Hirsholm and Deget. 7.5 m. — Soft bottom with stones. — Scarce 
vegetation: Desmarestia aculeata, Acrothrix gracilis, Desmar. viridis. 
gK. ‘/128. Hirsholm light-house in N.W., Frederikshavn Church in W.S. W., 19 m. — Soft 
bottom, no Alge. 
gQ. /:29. East end of Hjellens Rev by Frederikshavn. — 4—6 m. — Stones. Abundant 
vegetation: Halidrys siliqu., the three Laminaria species, Fuc. serralus, Furcellaria, 
Laurencia pinn., Polyides, Ahnfeltia, Corallina offic. 
1) L. Korperup ROSENVINGE: Phyllophora Brodiæi and Actinococeus subeutaneus. K. D. Vid 
Selsk. Biolog. Meddel. IX, 4, 1929. 
?) L. Korperup Rosenvince: The Reproduction of Ahnfeltia plicata. K. D. Vid. Selsk. Biolog. 
Medd. X, 2, 1931. 
63° 
