90 



usually two or more crowded together. Only in the dwarfed plant represented in 

 fig. f8 D have I seen the antheridia situated directly on the filament, but in this 

 case the filament was only two-celled. The juvenile stages of the epigynous an- 

 theridia show that these antheridia are really terminal, while the trichogyne rises 

 as a lateral outgrowth from the subterminal carpogonium (fig. 18 E, H), a case hith- 

 erto unknown among the Floridese. I have repeatedly, in material preserved in 

 alcohol, observed a little globular body lying immediately outside an empty anthe- 

 ridium or at a slight distance from it (fig. 18 F, D); as it agreed in size with the 

 spermatia adhering to the trichogynes (fig. C, K, L), I have no doubt that they were 

 really spermatia. Probably a spermatium is often transferred from an epigynous 

 antheridium to the trichogyne of the supporting carpogonium. After fertilization 

 the ventral part of the carpogonium grows oul into a slightly inwards curved fila- 

 ment which becomes 3-celled. The trichogyne is pushed outward so that it be- 

 comes situated on the convex side, on the second cell of the filament (fig. C). The 

 two lowest cells give otT several branches, while the uppermost cell produces a 

 carpospore (fig. C). Possibly the primary filament of the gonimoblast may some- 

 times consist of more than three cells. The lateral branches obtain a dift'erent 

 length, some becoming relatively long, articulated, curved and branched, others 

 remaining short and in part apparently unicellular, producing a carpospore without 

 division. The mother-cells of the carpospores have about the same form and size 

 as the sporangia. The trichogyne or the lowest part of it can be seen long after 

 fertilization on the second cell of the main filament; even in mature cystocarps a 

 slight remnant of it is sometimes to be seen, (fig. A). The emptied epigynous an- 

 theridium is also often to be found some time after fertilization; it is then situated 

 on Ihe first cell of the main filament (fig. /, K). 



While the plants often attain a length of 200 fi, very reduced plants also 

 occur, consisting of very few cells (fig./), /i). In the plant shown in fig.fi there 

 was only developed one filament consisting of one cell only, bearing a hair, a car- 

 pogonium with epigynous antheridium and a lateral outgrowth the character of 

 which could not be determined. 



The species differs from all more exactly described species of this group 

 through the position of the sexual organs, the form of the cystocarps and the 

 belt-shaped chromatophore. It may have been observed earlier, however, and pos- 

 sibly some of the plants mentioned under the name of Callithamnion minutissimum 

 have belonged to this species. Zanaudim's species of this name (Synops. Alg. mar. 

 Adr. 1841 p. 176; Hauck, Oesterr. bot. Zeitschr. 1878 Taf. II fig. 7— 8), however, be- 

 longs not to this group; and as to Suhr's species (Kutzing Spec. alg. 1849 p. 640, 

 Tab. phyc. XI tab. 57), it is impossible to identify it from the description and figures. 

 On the other hand, the specimens referred to that species by Crouan (Alg mar. du 

 Finistere No. 114, Florule du Finistere p. 134) show so much resemblance with the 

 species here described, that they might probably be identical. This, however, 

 cannot yet be decided with certainty as the specimens of Crouan bear no sexual 



