- 345 — 



seem thus to consist of pectose. I think the trabeculæ are to be regarded 

 as rest of the intercellular substance of the frond, which in earlier stage 

 of developement is solid. 



In a single place I have met with specimens which are to be re- 

 ferred to the f. cornucopiæ Lyngb., and at Eskifjöröur I met with typical 

 specimens of f. attenuata Ahlner, which by Strömfeit (1. c.) is recorded 

 from Eyjafjöröur and Eyrarbakki. 



The large specimens of f. genuina mentioned by Strömfeit (1. c. p. 53) 

 and by him identified with var. maxima auctt. ? belong to Monostroma 

 Grevillei var. intestiniformis (see p. 351). Strömfeit moreover mentions 

 (1. c.) some crisped and spirally twisted specimens of f. genuina, which 

 he found cast ashore at Isafjöröur. These specimens are in Strömfelt's 

 Herbarium determined as Enteromorpha intestinalis f. crispa, but one of 

 the specimens is a typical Enteromorpha intestinalis f. micrococca (Kütz.), 

 another specimen is a Monostroma sp. (M. undulatum Wittr. ?) and the 

 remaining plants are a crisped form of f. genuina much resembling some 

 specimens gathered by Lundbeck in NW. Iceland, Önundarfjöröur, in a 

 depth of 14 fathoms. The fragments collected by Lundbeck seem to 

 belong to very large specimens. The largest fragment was 70 cm. long 

 and 0,5—2 cm. broad in dry condition. These fragments are for the 

 most part unbranched, but some large prolifications, up to 30 cm. long 

 and 0,5 cm. broad, are occurring; they have the cells more or less arranged 

 in rows and bear again short prolifications, some of which only consist 

 of 1—2 cell-rows. The short prolifications are sometimes bifide above. 

 The thickness of the frond is 29 the cells are in transverse section 

 20/* high and 12/* broad, the inner wall 5// and the outer wall 4// thick, 

 and both walls are not seldom of the same thickness. In some respects 

 these plants remind of f. proliféra, but are, I think, to be regarded as a 

 large and branched f. genuina. 1 think that the plants have been growing 

 nearer the coast, probably at low-water mark, and that they have been 

 removed down to a depth of 14 fathoms by the currents. 



The f. genuina occurs especially in tide-pools in the upper part of 

 the litoral region, but is also met with at low-water mark. Fructiferous 

 specimens have been collected in April — October. 



f. micrococca (Kütz.) Rosenv. 1. c. p. 957. 



The Icelandic specimens are 2 mm. — 12 cm. high, about 1 mm. broad 

 and not seldom proliferous in the lower part of the frond. The thickness 

 of the frond is varying from 15 — 38 fi. The inner walls of the cells are 

 usually very much thickened and they form up to 2 1 3 of the whole thick- 

 ness of the frond. The thickness of the inner walls is, in the lower 

 part of the frond, varying from 7 — 26/* and the thickness of the outer 



