ca 
The fronds spring singly or several from a flat or cushion-shaped attachment 
disc (fig. 582). The branches arise at some distance below the apex; they are some- 
Fig. 582. 
Lomentaria clavellosa. A, small plant with 
cystocarps from Skagerak off Lonstrup, 
August. 33:1. B, lower portion of plant 
growing on Desmarestia aculeata, Hirsholm, 
October. 4.7: 1. 
times opposite, more frequently alternate, biseriate 
and the fronds are therefore often flat, but the 
branches may also issue from all sides of the 
branches. When the branches are regularly oppo- 
site or alternating, distichous at regular inter- 
vals, it seems probable that the branches corre- 
spond to the verticils in Chylocladia, and the regions 
where they are inserted to the diaphragms. Adventi- 
tious branches with indefinite position may occur 
later; they are much smaller than the primary 
ones. Some shoots grow out and obtain a similar 
length and character to those of the main shoot, 
others remain short, but there are all transitions 
between the long and the short shoots. I have 
once met with a branchlet ending in an attach- 
ment disc (fig. 583); it occurred as a branch of 
the second order at some distance from the base in 
a specimen growing on the Bryozoan Valkeria uva. 
The principal branches come near to the 
main frond in length and thickness; the latter 
attains a diameter of 1 to 1.5 mm. The branches 
of higher orders are much narrower, often very 
thin. Specimens referable or approaching to f. sedifolia have not been met with at 
the Danish coasts; the specimens growing here are always 
very slender. 
The young portions of the frond still in develop- 
ment are usually beset with numerous hyaline hairs, 
like those in Chylocladia kaliformis, but much thinner 
and shorter; they are about 2.5 w thick. They were ob- 
served at all the seasons, where the species was generally 
met with (May, July to October), though they were not 
met with in all the specimens observed. 
The antheridial sori appear, as shown by Ky in 
(1923, p. 47), as patches on the branches of the last or 
penultimate order, probably always in particular male 
plants. The cells producing the antheridia (spermatangia) 
bud off from the small outer cortical cells as small 
Fig. 583. 
Lomentaria clavellosa. A branch 
ends in an attachment disc. 12:1. 
colourless cells rich in protoplasm and containing one nucleus (mother cells of the 
spermatangia Kyrın l.c., fig. 33). Specimens with antheridia were observed once in 
Skagerak, on the Ist of August, and once in Northern Kattegat, on the 13th of July. 
