272 



The plant forms small low tufts about 1 1 ] / 2 cm high; it 

 was found near the surface of the sea, where is was constantly 

 washed by the waves. It has four pericentral cells (Fig. 2676). 



The base consists of creeping decumbent filaments fastened 

 to the subst r atum by means of rhizoids breaking out from the 



lowermost cells in the fila- 

 ment, sometimes two from 

 the same cell (Fig. 267 a). 



The thicker basal cells 

 are about 150^, sometimes 

 up to 200 ft thick and the 

 length of the cells about 

 125^; but these filaments 

 are often much thinner, some- 

 times not more than 60 /;., 

 and the length of the cells 

 about 100 . The creeping 

 filaments bend upwards in 

 their upper end, forming in 

 this way an even transition 

 to the erect filaments (comp. 

 fig. 267 a). The latter, too, 

 are often provided with hap- 

 ters which fix themselves to 

 neighbouring filaments, ser- 

 ving in this way to keep the 

 tuft together. 



The erect filaments, whether they issue from the creeping fila- 

 ments or are the upwardbent summits of these, taper evenly towards 

 their summit. In the basal part they are about 100^ thick and 

 the cells about 150 /^ long; near the summit the filaments are 

 mostly only half as broad as at their base. In the thinner fila- 

 ments the cells are sometimes three times as long as the diameter 

 of the filament ; f . i. a filament was about 60 jut thick and the 

 cells about 175 u long. 



While in the older parts of the thallus the filaments are al- 

 most cylindrical, the segments in the young parts are often sub- 

 sphaerical or barrelshaped, and the filaments in this way get a 

 moniliform appearance (Fig. 268). 



The branches issue without any connection with the trich- 

 oblasts (Fig. 269). The latter are developed upon each seg- 



Fig. 267. Polysiphonia sphserospora nov. 



spec, a, Base of a filament with rhizoids. 



b. transverse section of a filament. 



(a, about 50:1, b, 130:1). 



