79 



into spores, being provided with a thick firm wall, of a much denser consistency 

 than the gelatinous wall of the vegetative filaments. The akinetes are only sur- 

 rounded by a thin common membrane, much thinner than the wall of the vege- 

 tative cells, and it is thus beyond doubt that the walls of the akinetes have risen 

 by transformation of the innermost layers of the original gelatinous wall, and these 

 cells thus agree completely with the conception of akinetes by Wille. In some 

 cases the akinetes are close together, in others they are separated. They are partly 

 ellipsoidal or oblong, partly globular, measuring 8,5 to 10,5^ in transverse diameter, 

 up to 15 n in length. In fig. 17 C a free akinete is to be seen and two emptied 

 cells which have contained an akinete. As shown in fig. 17 C and D, the formation 

 of akinetes may take place in very small plants. 



As mentioned above, I have no doubt but that the specimens from the Danish 

 waters really belong to Asterocytis ramosa, though it seems that the species does 

 not attain in these waters the same dimensions as e. g. on the Norwegian coasts. 

 The frequently occurring unbranched individuals do not represent a distinct species 

 but only a reduced form, f. simplex (Lak.). 



The species has been found with certainty in some places in the Smaaland 

 Waters and in the Baltic, but is probably widely distributed in brackish water. I 

 have formerly noted it from Holbsek Fjord and from Kertinge Vig, but omitted to 

 keep the specimens. It has been found in shallow water near land, fixed on Poly- 

 siphonia violacea and nigrescens and Ceramium, only in summer (July to September). 



Localities. Ks : (Holbaek Fjord). — Sb: Kertinge Vig by Kerteminde. - Sni: Kragevig; off 

 Fetersvserft ; Guldborgsund, near Vennerslund. — Bb: Ronne, the reef S. of tlie town. 



B. FloridecB. 

 II. Nemalionales. 



J. Agardh, Species genera et ordines Algarum, Vol.11, pars II, Lundse 1851 — 52; Vol.111, 1876. 

 E. BoRNET, Deux Chantransia corymbifera Thuret. Acrocliaetium et Chantransia. Bull. soc. hot. France, 

 tome LI, Sess. extr. 1904 p. XIV— XXIll, pi. I. 



E. BoRNET et G. Thc ret, Recherches sur la fecondation des Floridees. Annales des sc. nat. 5e serie, 



VII, 1867. 



— — , Notes algologiques. Fasc. I. Paris 1876. 



F. B0RGESEN, Marine Algae. Botany of the Faeroes. Part II. Copenhagen 1902. 



F. S. Collins, Acrocliaetium and Chantransia in North America. Rhodora, Oct. 1906. 



E. de Janczewski, Note sur le developpement du cystocarpe dans les Floridees. Memoires de la Soc. d. 



sc. nat. de Cherbourg. Vol. XX. 1877. 

 H. Kylin, Zur Kenntnis einiger schwedischer Chantransia-Arten. Botaniska Studier tillagnade F. R. Kjell- 



man. Uppsala 1906 p. 113—126. 

 — , Studien fiber die Algenflora der schwedischen Westkuste. Upsala 1907. 



G. Murray and Ethel S. Barton, On the Structure and Systematic Position of Chantransia. .Journ. Linn. 



Soc. Vol.28. 1891. 



C. Nageli, Beitriige zur Morphologic und Systematik der Geramiaceae. Sitzungsber. d. Akad. d. Wiss. 

 Munchen 1861. p. 401— 415. 



