168 Algae. 



latter are certainly not to be regarded as unripe, not fully divided 

 sporangia. 



The antheridia (spermatangia) were found in Lithoihamiiioii Le- 

 normandi to be produced on the surface of great bushes extending 

 from the periphery towards the centre of the conceptacle, as pre- 

 viously described in L. polymorphum] that is perhaps a generic 

 character. In Lithophyllum Corallinae, the isolated spermatia lound 

 in the conceptacle contained two nuclei, an interesting fact, as 

 spermatia containing two nuclei have formerly only been observed 

 when fixed to the trichogyne but not at an earlier term. 



While as a rule the carpospores are only produced at the peri- 

 phery of the large disc-cell in the cj^^stocarpic conceptacles the 

 author has found that in Lithothamnion Lenovmandi, in L. poly- 

 morphum and sometimes also in Corallina officinalis, they also arise 

 from various points of the bottom of the conceptacle; but it could 

 not be stated whether the aberrant positicn of the carpospores is 

 founded on the fact that the disc-cell is more irregularly lobed or 

 whether it must be otherwise explained. 



Of the 7 species of Melohesia described, 5 are new {M . supiana, 

 limitata (= M. Lejolisn f. limitata Fosl.), Fosliei, trichostoma and 

 microspora). The author finds a good distinctive character between 

 this genus and the much resembling subgenus Dermatolithoru oi 

 the genus Lithophyllum, transverse pores never occurring between 

 the upright cellseries proceeding from the basal layer in Melohesia, 

 whereas such are present in all Lithophyllum species. On the other 

 hand , transverse fusion is of common occurrence in the Melohesia 

 species. The orifice of the antheridia-conceptacles was, in lour of 

 the species mentioned, often found drawn out in a spout, as first 

 described by Mrs. Weber- van Bosse in the case of M. Lejollsii. 

 This is, however, not a constant character, as it maj" frequenth' be 

 lacking in all the species concerned. 



Gloiosiphoniaceae. The germination and the development of the 

 antheridia is described in Gloiosiphotiia capillaris. 



The paper terminates with some general remarks on the 

 Cyyptonem,iales. 



Intercalary cell-di visions, which do ordinarily not occur 

 in the Florideae, have been noted in some cases among the Cryp- 

 tonemiales. So in Dumontia incrassata, in the short-celled filaments 

 which grow out from the basal disc and form the upright filaments 

 (Brebner), and in the radial filaments forming the basal layer in 

 Hildenhrandia prctotyptis. Further, in several Corallinaceae, the 

 cell-filaments terminate in a covering cell which is incapable of 

 division, while the penultimate cell takes over the function of the 

 terminal cell as an initial ohe. 



Cell-fusions have not only been observed in almost all the 

 Corallinaceae observed but also in various Squatnariaceae. In Hil- 

 denbraiidia they were not found. They are considered important 

 as facilitating connection between cells and celi-filamentg not directly 

 in communication by plasmacontinuity. 



Alternation of generations and alternation of nu- 

 clearphases. In the diplobiontic Florideae (Svedelius), having 

 normal fertilization and tetraspores, there are thrce generations, a 

 sexual one and two diploid. generations: the gonimoblast and the 

 tetraspore-bearing plant (K 3^1 in, Buder, Renner) while in the 

 haplobiontic there are only two generations: the sexual plant an^ 

 the gonimoblast. To the latter belongs Halarachnioii ligulatum\ 



