F. Børgesen: Rhodophyceæ of the Danish W. Indies. 



279 



The antheridial stands (Fig. 279) are formed by the first side- 

 branch of the trichoblast. They are rather thick, subcylindrical, with 

 a nearly spherical, thick-walled, sterile, apical cell; sometimes two 

 are found. The fertile part is up to 200 « long and 60« broad. The 

 fertile trichoblasts are found in the summit of the filaments. The 

 antheridial plants are somewhat more slender than those with 



Fig. 278. Polysiphonia ferulacea Suhr, J. Ag. 



a, summit of a filament; of some of the trichoblasts the basal cell is drawn 



only, b, summit of a plant with tetrasporangia. 



(About 180:1). 



tetrasporangia and cystocarps, the diameter of the vegetative 

 filament reaching only about 150// — 200 ^i. 



The cystocarps (Fig. 280) are large, nearly spherical, with a 

 short stalk. They are about 350// long and broad. 



I have compared my plants with specimens belonging to the 

 Botanical Museum, Copenhagen, collected by Liebman at Vera 

 Cruz and determined by J. Agardh. Agardh had at first referred 

 these specimens to Polysiphonia breviarticulata but in Species Al- 

 garum, vol. II, pars III, p. 981, he alters this determination and 

 refers Liebman's plant to P. ferulacea. 



