66 Veit Brecher Wittrock. 



Among the specimens I have had occasion to examine, not one has had the 

 lower part of the thallus lel't; tlius the nature of the rhizo'id is unknown to me. 



Sterile specimens. I have seen but one such specimen. The cauloïd of 

 the thallus had branches of three degrees. Those of the l:st and 2:d degree were 

 mostly found in pairs, opposite to each other, more seldom they were single; those 

 of the 3:rd, on the contrary, were single. The lower part of this specimen I have 

 represented pi. 1, tig. 12. From the cauloïd proceed obliquely downwards two 

 rather long cells, of which I suppose the one, marked r/;, to be the rhizoïd, and 

 the other, marked ac, to be an accessorial (rhizine) branch on the basal cell of the 

 cauloïd, analogous to the one represented pi. 4, fig. 7 ac after a sterile specimen 

 of P. lytivcnsis nob. 



Measurements. Fertile specimens. The principal tilanicnt of the cauloïd 

 is on an av. 120 f.i thick. The limits of variation are 90 and 150 f.i. The branches 

 of the l:st degree are in general 90 ,« thick, varying between 70 and 115 i.i. Those 

 of the 2:d degree are also about 90 f.i thick, and those of the 3:rd degree about 

 85 II. The length of the vegetative cells varies between 6 and 20 times the 

 thickness. The inclosed cask-shaped spores (i. e. the single ones in the principal 

 filament, and the upper one in the pairs of twin spores) are on an av. 144 f.i thick 

 and 232 i.i long. The limits of variation are indicated by ^I'lH l^l 11°^ i". The lower 

 ones in the pairs of twin spores are on au av. 113 f.i thick and 179 /.i long. They 

 vary between *}'■ H and l^ /.i. The single cylindrical spores are on an av. 85 fi thick 

 and 135 p, long. They vary between \';- Jo, i?o, Its i"^- 



The measures of the sterile specimen are as follows: the principal fila- 

 ment 115—130 |H, the branches of the l:st degree 100—125 f.i, the branches of the 

 2:d degree 90—100 /.i, the branches of the 3:rd degree 75—80 /a, the rhizoïd (?) 

 95 fi. 



Affinities and Differences. This species shows a near relationship to P. pohj- 

 morpha nob. and P. 'Eoetthri (Roth) nob. Its most remarkable character is, that 

 the spores in the principal filament occur, as a rule, two and two end to end. 

 (If an exception from this rule takes place now and then, a subsporal branch has 

 been developed, as has been indicated above, instead of the lower one of the 

 spores.) The ramification is feebler in this species than in P. RodtJeri (Roth) 

 nob., but somewhat stronger than in 1\ pohjmorpha nob. 



8. Pithopliora Roettleri (Roth) Bob. 



Synon. Ccramhm Bocttkri Roth Catal. Bot. Ill, p. 123. 

 CJadophora acrosperma Kiitz. Phyc. gener. p. 265. 



„ Roettleri Kiitz. Spec. Alg. p. 409; Tab. Phyc. Band. IV, 



pag. 10, tab. 46. 



Diagnosis: Principal filament of the cauloïd part of the thallus 

 in fertile specimens on an average 165 ;« thick, with branches of three 

 degrees; branches of the first degree three in a whorl, branches of the 

 second and third solitary or opposite in pairs ; spores solitary (rarely in 



