19 
on Polysiphonia urceolata. Later I have found, on Flustra foliacea, some dises which 
I think must be referred to the same species; they differed in their slightly larger 
dimensions and in the margin being partly continuous, the filaments being united 
to the extremities. These discs were thus still more similar to Erythropeltis, but 
the filaments had always partly free endings. The filaments were 3,5—5 y thick, 
narrowest at the border, broadest in the middle of the frond. The spores were 
4—5 y in diameter. 
Localities, Sk: Off Hirshals (XO and YK), 11,5 to 15 meters, August. 
Goniotrichum Kitz. 
1. Goniotrichum elegans (Chauv.) Le Jolis. 
Le Jolis, Alg. mar. Cherb. p. 103; J. Agardh (1883) p.13; Berthold (1882) p.26; Hauck, Meeresalg. p. 518. 
Bangia elegans Chauvin, Mém. Soc. Linn. Norm. t. 6 (not seen); Rech. sur l’org. d. plus. genr. d’Algues, 
Caen 1842 p.33; Harvey Phyc. Brit. pl. 246. 
Ceramium ceramicola Fl. Dan. tab. 2207 fig. 2 (? not the description). 
This plant attains a length of at least 5 mm. in the Danish waters. The fila- 
ments are below up to 50 » thick, above they become gradually thinner and are 
at the summit only 15 » thick. The increase in thickness below is usually due 
only to the thickening of the gelatinous outer wall, the diameter of the cells not 
increasing, and the cells forming usually a single row. There may be, however, 
more than one cell at the same level. This was caused, in the cases examined by 
me, not by longitudinal division of the cells but by displacement of the cells, so 
that the growing axes became inclined, the cells dividing then as usually by walls 
perpendicular to the growing axis and becoming arranged in two irregular longitu- 
dinal rows, or even more than two cells may occur at the same level (fig. 15 E). 
The outer wall is usually uniform, limited outwards by a fine line. Sometimes, 
however, the cells are provided with a denser, special membrane. In the plant 
represented in fig.15 E a rather thick, dense cuticular-like outer-wall was visible 
in the lower part of the plant; the cells were here also provided with dense spe- 
cial membranes, and between these and the outer membrane a stratification was 
often visible. 
The ramification takes place in a manner reminding one of the so-called false 
branching of the Scytonematacew. The branches rise at a great distance from the 
end of the filament, a cell growing outward through the gelatinous wall, dividing 
by a wall perpendicular to the new direction of growth (fig. 15 B, C). The further 
growth results in the branch coming to form a direct continuation of the principal 
filament and often takes nearly the same direction as this, the upper part of the 
principal filament being more or less pushed aside and taking the appearance of 
a branch (fig. 16). The cell lying at the origin of the branches is divided by a 
transverse wall as well as all the other cells. New branches very often arise below 
the older; even in old filaments new branches may arise (fig. 15 A). 
10° 
