337 | 
The Alga here treated has been mentioned for a long time in my annotations 
under the name of Call. byssoides. As, however, it is doubtful whether it is warranted 
to refer it to the species of ARNOTT and Harvey and as the limitation of this spe- 
cies in regard to related forms is uncertain, I prefer to give to the species of the Da- 
nish waters the name of C. Furcellarie, because it is at all events identical with 
this species of AGARDH. It must then be left undecided whether it can be identified 
with the British species 
wholly or in part; I | 
must content myself with 
referring to SCHMITZ's re- 
marks on the synonymy 
of C. byssoides and related 
forms in his paper: Die 
Gattung Microthamnion in 
Ber. d. deut. bot. Ges. 1893 
pp. 280 and 283. 
The species occurs 
in all the Danish waters; 
it usually reaches only a 
length of 2 cm or a little 
more, in the inner waters 
Sf and Sb, however, it be- 
comes 3 cm and at Born- 
holm up to 4 cm high. 
The ramification has 
been treated at length by 
Kyrın (1907, p. 167) and Fig. 260. Fig. 261. 
by me (1920, P- 49). It is Callithamnion Furcellarie. Upper end of Callithamnion Furcellariæ. Up- 
less regular than in the plant from Fænø Sund, with irregularly per end of plant from Born- 
arranged branches and dispores. holm, with biseriate branches. 
other Danish species. The 70:1. 270 : 1. 
branches are, however, 
usually arranged in a spiral, but in several shoots the branches were irregularly 
arranged or more rarely biseriate (specimens from Bornholm). When the branches 
are arranged in a spiral, the angle of divergence is more variable than in the other 
species; the angle of divergence varied in the examined shoots from 67° to 131°. 
Not rarely did the direction of the spiral change in the same shoot. The branches 
are usually branched from the base, the first joint normally bearing a branch; but 
it happens now and then that the first joint is branchless, and in specimens from 
Bornholm several joints at the base of the branches were branchless. The spiral 
arrangement as a rule begins at a certain distance from the base, the first branches 
being irregularly arranged, sometimes, however, partly biseriate in a transverse or 
oblique plane. In several cases two branches of unequal size were found inserted 
