146 
The species occurs in all the Danish waters except the Baltic, growing in the 
littoral region, thus being out of the water at low-tide. It varies but little in shape 
in the different localities; it attains very often a length of ca. 20 cm., but larger 
specimens not seldom occur; thus specimens measuring 40 cm. were met with at 
Harboore and Gilleleje. It has been found in the months July to November; in 
the remaining part of the year it is probably represented by the creeping filaments 
described by Miss CHESTER which were, as mentioned above, observed by me in 
February. It may be supposed that the germination takes place immediately after 
the setting free of the spores but that the erect plants only develop in the next 
summer. I found however in November on the mole at Gilleleje young plants from 
less than 1 mm. to a few cms. in length; they would probably have perished during 
the winter, but possibly the basal portions would have been able to produce new 
erect fronds. i 
The species is said to be as a rule monoecious; I found it however most 
frequently dioecious in the Danish waters. In the proportionally few monoecious 
À specimens (about 10 per cent) I found the two kinds of 
2 sexual cells near to each other in all parts of the plant 
and there is thus no reason to believe that the dioecious 
specimens would have proved to be really monoecious 
N on closer examination. Antheridia occur in all the months 
Cy July to November, but in the last months they are in 
Cie TINS) a great measure emptied. Ripe cystocarps may occur 
Aine TD already in July; in August a great part of the spores 
are often set free as well as later, in November how- 
ever cystocarps containing most of the spores may still 
be found. 
In autumn or the beginning of the winter the plants gradually die, the 
assimilative filaments being the first destroyed. This may begin already in Au- 
gust, but on the other hand fairly well-kept specimens are to be found still in 
November. 
The species prefers agitated water; it therefore grows on the outer, not on 
the inner sides of the moles. It occurs on stones but also on wood, often together 
with Fucus. 
Nemalion multifidum. Antheridial 
branches at the ends of assimilative 
filaments. 340:1. 
Localities. Ns: Groins at Harbogre and Thyboren. — Sk: Hanstholm, on a boulder near 
land; Lenstrup (Warming); Hirshals (!, Bergs.); Skiveren, on wreck. — Lf: Oddesund; Struer; Ejerslev 
Ren. — Kn: Frederikshavn; harbour of Vesterø, Lesa; Hornex, Læsø (J.P. Jacobsen). — Ke: Gilleleje 
Lyngb.. !). — Km: Anholt harbour; Herringholm (Lyngbye). — Ks: Grenaa harbour; Tisvilde (C. Rasch); 
near Klintebjerg. Odsherred (J. Vahl); Isefjord: Nykøbing; Lynæs: off Nordskov; Ours; Holbæk Fjord: 
Bramsnæs Vig. — Sa: Kyholm, in the middlemost Fucus-zone: Szlvig (Hjalmar Jensen); Koldby Kaas; 
Hofmansgave (Hofm. Bg., Lyngb., C. Rosenb.); Juelsminde. — Lb: Bogense. — Sf: Redlok Grund off 
Nakkebølle Fjord: Svendborg; Birkholm; Rudkøbing. — Sb: Kerteminde; Korsør; Lohals. — Sm: 
Guldborg. — Su: Hellebæk; Helsingør; Humlebæk (Henn. Petersen); near Hveen (Ørsted); Trekroner 
near Copenhagen (Ørsted). 
