296 K.TELLMAN, THE AJÄiJE OF THE ARCTIC SEA. 



same tiiue, but becoraing only very slightly, if at all, lobed. The frond when bearing 

 zoospores has a length of 15 cm. by an almost equal breadth in its upper expanded 

 part; fig. 1. 



Its lowest part is formed by club-shaped cells with very gelatinized merabranes, 

 by the shaft-ends of which it is attached. The club-heads are fusiform, fusiform- 

 cylindrical, almost cylindrical, elongated-ovate, their cell-rooms being 5 — 10 /u.. in cross 

 section at their thickest part. In a transverse cut the club-heads are usually seen to 

 occupy one side of the frond, the shafts being placed on the other. This part of the 

 frond is 30—40 /u. thick; fig. 2—3. 



At a distance of two raillimetres from the callus the frond becomes monostromatic, 

 being formed here as well as farther upwards, as far as it is sterile, by cells the 

 rooms of which are four-angular in cross section with aciite or rounded corners. They 

 are soraetimes square, sometimes rectangular, in the latter case usually having their 

 greatest length in a parallal direction to the surface of the frond. The monostromatic 

 part is 40 — 45 f^i. thick; the rooms of the cells being 10 — 15 ,«. high, the wall is 

 accordingly of considerable thickness. The chlorophjd takes up sometimes the whole 

 room of the cell, sometimes only a part of it. In the middle of the frond the vege- 

 tative cells, as seen from the surface, are 4 — 5-angular with thick walls. Their longest 

 diameter is about 20 — 25 ,". ; fig. 4 — 5. The part of the frond bearing zoospores is 

 composed of cells the rooms of which are circular as seen from the surface, 10 — 17 ,m. 

 in diameter, with very thick walls. The rooms in cross section are either circular or 

 circular-elliptical with their long axis, 17 — 22 ,«., parallel to the surface of the frond; 



^g- 6-7. 



Habitat. This species is litoral, attached to other algas, especially Halosaccion 

 ramenfacewn, growing scattered on exposed coasts. Specimens with zoospores have been 

 collected at the end of July and the beginning of August. 



Geogr. Distrib. Known only from the Norwegian Polar Sea. Here it is scarce. 

 Its northernmost point is Gjesvo3r about Lat. N. 71°. 



Localities: Finmarken at Maasö and Gjesvar, local and scarce. 



Monostroma saccodeum nob. 



M. thallo callo radicali adnato, initio saccato, deiade raembranaceo, in lacinias oblongas, lanceolatas vel 

 ovatas, margine vel crispo plus minus decomposito-fisso; parte monostroraatica inferne .30 — 40, superne 25 — 30 

 ft. crassa, e cellulis constructa a fronte visis luraina rotundata; semicircularia vel 3 — 5 angulata inter se niem- 

 lirana crassiuscula separata, in seetione transvevsa thalli visis lumina cellularia verticaliter elliptica 15 — 17 //. 

 älta, 8 — 10 lata pniehentibus; corpore chlorophylloso lumen celUilare fere oranino explente. Tab. 28, fig. 1 — 10. 



Syn. Monostroma latissimum Kleen, Nordl. Alg. p. 41; saltera ex parte fide herb. 



Description. The present species agrees with M. Grevillei \n development, and is 

 related to it even in habit, although in structure the two plants are sharply distinguished. 

 The frond when young has the shape of an ellipsoidic or pyriformly cylindrical säck 

 or bladder, even 4 cm. in length, of a light grass green colour, almost without gloss, 

 with smooth wall, and attached l)y a callus radioalis; tig. 1 — 2. These bladders soon 



