INVERTEBRATA, ORYPTOGAMIA, MICROSCOPY, ETC. 1023 



founded on the species hitherto described by Suringar* and himself 

 as Laminaria japonica, and previously by Thunberg as Fucus sac- 

 charinus. The following is his diagnosis of the genus : — Radix 

 fibrosa ; stipes complanatus, evanescens in laminam e basi acute ovata 

 et firmiore, lineari-lanceolatam, fascia porcursam, in apicem juniorem 

 integrum et non dissolvendum longissime productam. Fructificatio 

 in parte inferiore et crassiore (?). 



New Endophytic Alga.f — Under the name Entodadia WittrocJcii, 

 N. Wille describes a new Alga endophytic or parasitic on two species 

 of Ectocarpus, E. siliculosus, and E. firmus, in a fiord in the neighbour- 

 hood of Christiania. It forms unbranched or slightly branched rows 

 of cells in the interior of the cell-wall of the host. Its cells contain 

 large starch-grains and parietal chlorophyll. All the cells may form 

 in succession four, eight, or perhaps a larger number of zoospores, 

 which escape through a circular opening in the cell-wall. 



New Genus of Oscillatorieae.:]:— In " Contributions to the Alga flora 

 of Wiirtemberg," Dr. 0. Kirchner describes under the name Clastidium, 

 a new genus of Oscillatoriefe belonging to tlie section Chamaesiphonca3 

 (Borzi), with the following characters : — Filaments short, unbranched, 

 without sheath, firmly fixed at the base, provided at the apex with a 

 thin, erect, unscgmented bristle ; cells scarcely distinguishable in the 

 young state ; afterwards cylindrical, finally spherical ; reproduction 

 by isolated gonidia resulting from the entire filament breaking up 

 into spherical cells. 



The only species, C. setigcrum, grows attached to filaments of 

 Cladophora, which it completely covers ; the bristle is delicate, about 

 0*05 mm. long; the cell-contents homogeneous, pale blue-green; the 

 entire filament, excluding the bristle, when mature, 0*028 to 0-038 

 mm. long, 0-0025 to 0-004 mm. thick. 



Clastidium is the only known genus of Oscillatoriea) provided 

 with a bristle, which is formed at an early period, and may be com- 

 pared to that of Coleochcete or Bnlbochcete ; no hormogonia have been 

 observed. 



Change of Colour in Oscillatorie8e.§ — P. Eichter states that too 

 much value must not bo j)laced on colour as a distinguishing character 

 of the species belonging to the genera Oscillatoria and Phorinidium. 

 Cohn considers the bright green colour of the Phycochromacoai to be 

 due to a mixture of green chlorophyll and blue phycocyan. According 

 to Richtcr, a deficiency of water is favourable to the formation of 

 phycocyan, and hence to a blue-green colour, in consequence of the 

 Kulubility of phycocyan in water. The same species will exhibit 

 diilbrent colours, according to the quantity of water in which it grows, 

 and other conditions. 



• ' AlgtB Japonicie,' p. 21. 



t • Christiania Vidcnsk. Forlinndl.,' 1880. Sco ' Bot. Centralbl..' i. (1880) 

 p. 571». 



X ' Jahreshpftc Vcr. fiir vatorl. Nnturk. Wiirtteniberg,' xxxvi. (1880) p. 1;"). 

 § ' Hot. Centralbl.,' i. (ISSO) p. (505-7. 



3 Y 2 



