601 
BuFFHAM reports (1884, p. 338) that he has met with “a fine plant, divided 
near the base, bearing tetraspores on one half and coccidia on the other”. If 
a similar case should be met with again, it would be of interest to ascertain 
whether the plant is really a single individual or if its origin might possibly be 
due to the fusing of two distinet individuals. 
The germination I have not observed; but according to Kyrın the germination 
of the carpospores begins with the formation of a disc-shaped body (“Keimscheibe’’) 
(1923, p. 53, fig. 34 e). 
Fig. 604. 
Plocamium coccineum. From Hirtshals, September (A) and from the Færûe Islands, May, collected by F. BORGESEN. 
Stichidia. A and B, optical longitudinal sections. C and D cross sections. E, undivided sporangium. F, ripe 
sporangium. 350 :1. 
Plocamium coccineum has only been met with in the North Sea and Skagerak. 
It has only been collected in the months of June to October, but this is due to 
the fact that dredgings in these waters have not been made in winter and spring. 
It has been found at depths from 2 to 18 metres in Skagerak, and a small spec- 
imen was found in the North Sea at 27 metres’ depth. It grows on stones and on various 
Alg® (Laminaria hyperborea, Rhodomela, Phyllophora membranifolia, Furcellaria). 
The Danish specimens agree with the typical North European form. Though 
the species has not been collected in winter and spring, it is evident that it is 
perennial. In specimens gathered in June the new shoots had a brighter colour 
than the older ones, and the old portions of larger plants are often largely covered 
with Membranipora pilosa. 
The fronds reach a length of up to 10 cm. Tetrasporangia and cystocarps 
D.K.D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd., VII, 4. 77 
