THE ALGAE OF BERMUDA. 147 



cystocarps appear as if terminal, as the short prolongation of the axis 

 is- liable to be mistaken for an involucral branch. In younger parts 

 the cells of the basal layer are seldom over 2 diam. long; in older parts 

 these cells may be up to 8 diam.; the corticating band does not in- 

 crease in width, but is as narrow and sharply limited in the longest 

 cells as in the others. 



4. C. NITENS (Ag.) J. G. Agardh, 1851, p. 130; P. B.-A., No. 1949; 

 C. rubrum var. nitens Agardh, 1824, p. 136. Harrington Sound, Jan., 

 Dec., Hervey; Inlet, Aug., Agar's Island, Fairyland, Nov., Dec., 

 and dredged down to 18 m., Dec., Collins. 



5. C. CLAVULATUM Agardh in Kunth, 1822, p. 2; P. B.-A., No. 

 1948; Centroceras clavulatum Harvey, 1853, p. 211, PI. XXXIII. C. 

 Rein; Kemp; Wadsworth, Harrington Sound, No. 18. As this 

 plant is abundant practically everywhere, we give no detail of stations 

 of our own collecting. It is very variable, and many species have been 

 proposed in the past, only to be found unworkable ; it may be that 

 some time a successful segregation will be made, but it can hardly 

 be done with habit characters, which are very inconstant. Tetra- 

 spores were found in Nov. & Dec., but no other fructification has been 

 observed by us. In the Kemp herbarium are specimens marked 

 respectively C. rubrum and C. fastigiatum, which belong to this species. 

 C. cryptacanthum reported by Moseley is a synonym. 



RHODOCHORTON Nageli. 



1. Saxicolous; prostrate filaments bearing erect filaments. 



1. R. speluncarum. 

 1. Endozoic; in tubes of bryozoans etc. 2. R. menibranaceuna. 



1. R. speluncarum sp. nov. Filamentis prostratis 3040 (j. diam., 

 membrana 4-5 /j. crassa, cellulis 2-3 diam. longis; rhizoideis brevibus 

 affixis, a parte media cellulae exeuntibus, in discum majorem min- 

 oremve desinentibus. Filamentis erectis cylindricis vel minime 

 diminutis apicem versus, e superfine superiore filamenti prostrati 

 exeuntibus, prope mediam partem cellulae, saepius rhizoideis oppositis, 

 24-30 /j, diam., membrana 2-3 /JL crassa, cellula inferiore 2-2^ diam. 

 longa, cellulis ceteris 3-4 diam. longis, cellula terminali rotundata; 

 filamentis erectis aut simplicibus aut ramis paucis alternatis vel 

 secundis prope apicem munitis. Fructificatio ignota. 



Prostrate filaments 30-40 /j. diam., wall 4-5 /j, thick, cells 2-3 diam. 

 long, attached by short rhizoidal branches issuing from the middle part 



