— 151 — 



and 7—10/^ broad, they are for the most [)art sessile, especially in the 

 marginal portion, but stalked sporangia are not rare in the central part. 

 The stalk is of varying length and composed of one or more cells. The 

 sporangia are usually thickest in the middle or sometimes at the base, 

 and consist usually of two series of loculi in the middle and one series 

 below and above. The chromatophores are small, disciform, 4—8 in each 

 ceil. Unilocular sporangia are unknown. 



I have also met with some fragments of an Ascocyclus on Laminaria 

 saccharina, fully agreeing with the specimens on Rhodymenia. 



The species differs from Ascocyclus orbicularis Magn. and A. affinis 

 Svedel. by shorter ascocysts and the presence of assimilative filaments. 

 From A. hispanicus Sauv. it differs by the number of the chromatophores, 

 uubranched erect filaments and the shape of the ascocysts, amongst other 

 characters. From A. sphserophorus Sauv., to whicli it comes neai'est, it differs 

 by the shape of the ascocysts, which in A. islandicus always are sessile in 

 A. sphferophorus sometimes stalked. The sporangia of A. islandicus are 

 somewhat narrower and the assimilative filaments somewhat longer tlian 

 in A. spliKrojihorus. The differences mentioned between A. islandicus 

 and A. sphsrophorus were probably not of sufficient value to keep them 

 specifically distinct, if the number and shape of the chromatophores were 

 the same. The chromatophores of A. spha?rophorus are, as far as 1 know, 

 unknown, and I prefer therefore to regard the Icelandic plant as a distinct 

 species, at all events provisionally. 



Gathered with plurilocular sporangia in Sept. 



NW. I eel. Kolbeinsa. 



Fam. Ectocarpacese. 



Microsyphar Poly$i|ilioiii% Kuck. Beitrage p. 29. 



I have found this species growing in Polysiphonia urceolala and 

 Callithamnion scopulorum. Gathered with sporangia in June and August. 



NW. I eel. IsafjorOur (CO.). 



SW. Icel. Brimnes, Einarslon; Reykjavik. NjarLlvik (CO.). 



Strebloneina a'cldioides Rosenv. Grl. Havalg. p. 894-, Deux. Mem. p. 80. 



Phycocelis aicidioides Kuck. , Bemerk. I, p. 234. 



r have found this species growing in Laminaria saccharina and Lami- 

 naria digitala f. cucuUata in the upper sublitoral region. 1 have also 

 met with it in literal pools in Laminaria saccharina f. phyllitis. Gathered 

 with plurilocular sporangia in July — September. The Icelandic plants 

 agree well with the description and figures given by Rosenvinge (1. c.) 

 and Kuckuck (1. c). Rosenvinge's original preparations of the species agree 



