66 



Veit Brecher Wittrock. 



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

 lower part of the thallus left; thus the nature of the rhizo'id is unknown to me. 



Sterile specimens. I have seen but one such specimen. The cauloid 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, fig. 12. From the cauloid proceed obliquely downwards two 

 rather long cells, of which I suppose the one, marked rh, to be the rhizo'id, and 

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

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

 of P. hewensis nob. 



Measurements. Fertile specimens. The principal filament of the caulo'id 

 is on an av. 120 /< thick. The limits of variation are 90 and 150 ^t. The branches 

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

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

 85 /i. 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 /n long. The limits of variation are indicated by t 1 h ' 2 1 1 1 5 ^- HI /«. The lower 

 ones in the pairs of twin spores are on an av. 113 n thick and 179 (x long. They 

 vary between ^ and ™ /a. The single cylindrical spores are on an av. 85 [i thick 

 and 135 fi long. They vary between \ h - J° J* \f 5 /li. 



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

 ment 115 — 130 |tf, the branches of the l:st degree 100 — 125 fi, the branches of the 

 2:d degree 90—100 fi, the branches of the 3:rd degree 75 — 80 ft, the rhizo'id (?) 

 95 fi. 



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

 morpha nob. and P. Eoettleri (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. Eoettleri (Roth) 

 nob., but somewhat stronger than in P. polymorpka nob. 



8. Pithophora Roettleri (Roth) nob. 



Synon. Ceramium Eoettleri Roth Catal. Bot. Ill, p. 123. 



Claclophora acrosperma Kiitz. Phyc. gener. p. 265. 



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



pag. 10, tab. 46. 



Diagnosis: Principal filament of the cauloid 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 



