27 



latis 10 p longis, in superior! fere 2 /j. latis et 20 fj. et ultra longis 

 composita. Chromatophorum parietale, pyrenoide laterali munitum. 



Monosporangia aut sessilia aut pedicellata aut in ramulis 

 posita oblonga, 14 16^ longa, 6 8/* lata. 



The base of the plant (Fig. 19 c) consists of creeping epi- 

 phytic filaments which are mostly free or somewhat fused together. 

 The cells in the basal part are about as long as broad or a little 

 longer. They are 5,5 fj. broad. 



From the cells in this disc erect filaments arise. At the base 

 these filaments (Fig. 19 a, b) are about 5,5// thick; 

 they taper slowly towards the summits and often 

 end with long hair-like prolongations in which the 

 cells are only about 2// wide. In the lowest part 

 of the filaments the cells are about 10 p. long, in the 

 upper end on the other hand they often reach a 

 length of about 20 // and more. 



The chromatophore (Fig. 20) is parietal with 

 irregular prolongations and contains a large pyrenoid 

 lying near the wall of the cell and protruding deeply 

 into the interior of the cell. 



The filaments are not much branched, often not at 

 all in the lowest part and bearing here for the most F - 9Q 

 part only short branches with sporangia. In the chaetium gm- 

 upper part the filaments give off multilaterally p^o^fda- 

 situated branches, mostly only a few and these ment with 

 branches ' are as mentioned above often terminated sp /^out a ' 

 by thin hair-like prolongations. 800 : 1). 



The branchlets bearing the sporangia are mostly 

 multilaterally placed upon the lower part of the principal bran- 

 ches. But uniseriated branches also occur especially higher up 

 in the filaments. 



Most of the branchlets are unicellular, bearing a single or 

 sometimes two sporangia, but two-celled branchlets are also 

 common while others with several cells are found more rarely. 



Sessile Sporangia are scarce but they occur now and then, 

 especially in the upper end of the filaments. 



The sporangia (Figs. 19 a, b, Fig. 20) are linear oblong, about 

 14 16 f* long, 6 8, broad. 



This species was found upon old leaves of Sargossum vulgare 

 growing here together with several other species. 



Only found once in the Harbour of St. Thomas. 



