413 



media parte caespitum) , nunc ascendentibus , basi curvato , vix 

 inflato affixis. Vag in i s tenuibus hyalinis, non lamellosis. Tricho- 

 matibus purpureis vel purpureo-violaceis , 3 ju ad 5 ti crassis, 

 apicibus saepius modice incrassatis et ad genicula contractis. Arti- 

 culis diametro aeqvalibus usqve ad 3-plo brevioribus, dissepimentis 

 saepe indistinctis, protoplasmate granuloso; cellulis apicalibus rotun- 

 datis, cellulis ceteris majoribus. Heterocystis parvis sphaericis vel 

 subsphaericis , basilaribus , singulis (rarissime paucis intercalaribus 

 in parte basilari trichomatis). Sporis non visis. 



Hab. in consortio Calothricis confervicolae in Fuco vesiculosa 

 et serrato in mari Kattegat ad insulam Læsø mense januarii 

 (Rosenvinge). 



Of the species hitherto known this one is nearest to M.grisea; 

 only deviating from that other one in manner of growth, having sepa- 

 rated rows of small tussocks, and purple colour, smaller dimensions, 

 and the filaments not swelled at the base or at least very little. In its 

 outer appearance it resembles Amphithrix Laminariae Kuckuck (Be- 

 merkungen z. marin. Algenvegetation von Helgoland 1894) according to 

 the description of this species. 



90. Tolypothrix tenuis Kiitzing emend. 



Phycologia generalis, p. 228, 1843; Species Algarum, p. 313; 

 Tabulae phycologicae, II, p. 9. 



Tolypothrix tenuis Bornet & Flahault. 



Revision des Nostocacées hétérocystées , fragment III. p. 122, 

 e specim. authent. in herb. Hafn. 

 Tolypothrix lanata Wartmann. 

 Rabenhorst, Algen, Nr. 768, 1858. 

 Tolypothrix lanata Bornet & Flahault. 



Revision des Nostocacées hétérocystées, fragment III, p. 120, 

 e specim. authent. in herb. Hafn. 



T h alio densius vel laxius caespitoso-floccoso, rarius pannoso, 

 aerugineo aut demum luteo-fusco. F il i s usqve ad 2 cm. longis, 

 7,2 fi ad 16,8 fi crassis, saepius abundanter pseudo-ramosis, ramis 

 erecto — patentibus. Vagin i s initio tenuibus hyalinis, aetate pro- 

 vecta crassis lamellosis, luteo-fuscis, haud raro ad basim ramorum 

 inflatis. Trichomatibus 5,6 ß ad 12,8 a crassis, aerugineis vel 

 olivaceis saepius ad genicula non contractis. Articulis ante divi- 

 sionem qvadratis usqve ad diametro duplo longïoribus , protoplas- 

 mate granuloso farctis. Heterocystis cylindricis , subsphaericis vel 

 discoideis, singulis vel 1 — 5 seriatis, saepius hyalinis. 



It seems to me, that the distinction between T. lanata and T. 

 tenuis maintained by Bornet & Flahault is an impossible one. In 

 reading the descriptions of those two species in the Revision des 



