what more developed plants showed 
an adventitious shoot issuing from 
the stipe, produced from a super- 
ficial cell (fig. 424 B, C, E). The 
normal branching at the apex seems 
only to begin when the plants have 
attained a size of about 3 mm. In 
a young 7 mm high plant the pri- 
mary shoot was terete at the base 
but a short distance upwards 
flattened and at a higher level 
branched in the usual way. The 
young fronds are fixed to the sub- 
stratum by a circular basal disc 
composed of densely united radiat- 
ing cell-filaments. In a more ad- 
Fig. 425. 
Female sexual shoots. 
partly in the third joint of the branches. 
probably arise subterminally in the main axis *. 
The procarps arise 
In B a procarp will 
200 : 1. 
Odonthalia dentata. 
vanced stage the basal disc is a flat expansion having a circular or lobed outline; 
the regularly radiating filaments are united to the margin. 
The organs of reproduction are as a rule confined to small adventitious shoots 
+ 
Fig. 426. 
Odonthalia dentata. Female sexual branchlets 
with ripe and aborted cystocarps. See text. At 
:* procarps are apparently developing in the last 
segment cut off from the apical cell. 
4"95':1. B 50:1: 
borne on the margin of the frond. 
The antheridial shoots are according to 
BurFHAM (1893) and FALKENBERG (1901, p. 607) 
pale simple or bifid leaflets, the surfaces of which 
are covered with antheridia. They have hitherto 
not been observed in the Danish waters. 
The female shoots are much branched, 
slightly winged or quite cylindrical. Accord- 
ing to FALKENBERG (1901, p. 606) the pro- 
carps constantly arise in the second joint of 
the fertile shoot. That is, however, not always 
the case, for I not unfrequently found them 
in the third joint (fig. 425 A, C), and it seems 
that they may also arise in higher situated 
joints (fig. 426 B, to the right). The sterile 
upper part of the procarp-bearing shoots (the 
calcar) is as a rule unbranched, incurved, but 
it not unfrequently happens that it is branch- 
ed and produces new procarps (fig. 426). It 
seems that the end of the shoot may also 
produce a procarp arising from the last seg- 
ment cell (figs. 425, 426*). 
The tetraspore-bearing shoots are cylindrical, 
D. K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII. 3. 59 
