— 147 - 



p. 106) and Börgesen (Fær. Alg. p. 421). On old specimens of Rho- 

 dymenia palmata I have occasionally met with plants having short rhizoids 

 (Fig. 5, e). I have only met with basal hairs, the base of which is enclosed in a 

 sheath as mentioned by Börgesen (I.e.). 

 The erect filaments are considerably 

 varying. Specimens, belonging to the 

 typical form, with richly branched 

 erect filaments, fully agreeing with 

 Reinke's figures (Atlas I. c.) and 

 Rosenvinge's fig. 19, .£> (I.e.) are not 

 rare in my material. I have met 

 with an other form (fig. 6) growing 

 on Rhodymenia, precisely resembling 

 Rosenvinge's fig. 20 (1. c), with the 

 erect filaments branched or unbranched 

 and the sporangia stalked or sessile. 

 A third form (fig. 7) growing on Ghætomorpha and Cladophora resembles 

 somewhat the last-named, but is more poorly developed. The erect fila- 

 ments are short, branched or unbranched; the sporangia have usually a 

 short stalk consisting of one cell or they are sessile. The sporangia are 

 14 — 36 ^ long and 4 — 1 ji thick. The hairs are about 4// thick at the 

 base, and the thickness of the basal disc is 5 »i. 



Fig. 6. 



Myrionema globosum (Rke.) Fosl. 



f. with unbranched plurilocular 

 sporangia, sessile or stalked. (316: 1.) 



Fig. 7. Fig. 8. 



Myrionema globosum (Rke.) Fosl., f. growing on Ghætomorpha tortuosa. 

 Fig. 7 (300 : 1), a shows a portion of the margin consisting of creeping filaments 



b and c fragments of an entire margin. 

 Fig. 8. a, b 300: 1; c, d, e 316: 1; a shows a sterile filament and an emptied 

 plurilocular sporangium; b a basal hair enclosed below in a sheath; c a stalked, 

 terminal sporangium and a young erect filament; d, e two stages of ramified 



plurilocular sporangia. 



On account of the unbranched filaments with terminal sporangia, the 

 species reminds one of Myrionema balticum (Rke), as Rosenvinge (1. c.) 

 points out, on the other hand it comes near to M. Gorunnæ, and certain 



