64 Vert Brecner Wirrrock. 
Measurements. Fertile specimens. Cauloid part. The vegetative cells 
of the principal filament are on an average 105 w thick. Specimens of the first 
type of ramification have in general thicker cells; those of the second narrower. 
The greatest observed thickness (in the former) is 130 w, the least (in the latter) 
85 «. The branches of the l:st degree are on an av. 74 w thick. They vary 
between 45 mw and 105 «w. The branches of the 2:d degree are on an ay. 53 «1 
thick. They vary between 45 and 60 w. The length of the vegetative cells is less 
in specimens of the first type of ramification than in those of the second. In the 
former they are in general 4—6 times as long as thick, but in the latter 6—8 times. 
The shortest vegetative cells are scarcely any longer than the thickness; but the 
longest as much as 20 times as long as thick. —- The inclosed cylindrical spores 
are on an ay. 63 « thick and 88 « long. The limits of variation are indicated by 
th. 45 45 19 4. The inclosed cask-shaped spores are on an av. 104 w thick and 
157 w long. The limits of variation are indicated by 8° °° 1% uw. The inclosed- 
125, 115, 
spores of irregular shape are on an ay. 121 « thick and 133 a long. They vary 
between 7 and 3 «. The lower of the twin spores are rather thick but very 
short, on an av. 117 « thick and 103 « long. The terminal subconical spores have 
on an ay. the same thickness as the inclosed, viz. 63 u, but are considerably longer, 
measuring on an av. 155 uw. The limits of variation are indicated by oe ce mo ori 
The cask-shaped terminal spores, narrowing towards their top, are on an ay. 95 w 
thick and 148 « long. The limits of variation are indicated by 1" 40 ios gna 
Rhizoid part. In the only rhizoid I have seen, the vegetative cell was 90 u 
thick; the inclosed spore 90 w thick and 95 « long, and the terminal spore 90 « 
thick and 175 w long. 
The single sterile specimen that I have seen had the principal filament 
125 w, the branches of the I:st degree 75 « and the branches of the 2: degree 
70 « thick. 
Affinities and Differences, There is no need to compare this species to any 
but its nearest relatives, P. Zelleri (v. Mart.) nob. and P. Roettleri (Roth) nob. 
It is most clearly distinguished by its very numerous inclosed cylindrical spores 
and by the subconical terminal ones. Besides, it differs from the two species men- 
tioned by: smaller dimensions and less powerful ramification. 
7. Pithophora Zelleri (v. Mart.) nob. 
Synon. Cladophora Zelleri v. Mart. Die Tange, p. 111. pl. 2. fig. 1 (the 
figure not good). 
Diagnosis: Principal filament of the cauloid part of the thallus in 
fertile specimens on an avy. 120 w thick, with branches usually of two 
degrees, solitary or opposite in pairs; spores partly inclosed, partly 
terminal; the spores of the principal filament regularly in pairs, the 
spores of the branches commonly solitary; the upper one in a pair 
of twin spores (and the solitary now and then occurring in the principal 
