456 



stem, but in the latter, however, only in the basal and not in the 

 inflated part. I have now examined the stem and especially the 

 basal part of the stem of numerous specimens of L. færoensis 

 without, however, tinding the least indication of muciparous canals 

 which are doubtless wanting here, though they are distinctly de- 

 veloped in the lamina and exactly resemblc those which Kjell- 

 man found in L. saccharina and figured in N. I., pp. 292— 3 (234—5), 

 tab. 25, fig. 7. 



The length of the stem varies considerably according to whether 

 the plant grows in shallow or deep water; thus, at the head of 

 Kalbakfjord in quite shallow water — a few feet — I found spe- 

 cimens with lamina measuring 3 — 4 feet and the stem hardly a 

 foot long, while in normally developed specimens the stem and 

 the lamina are of about the same length; in L. longicruris, however, 

 the stem is reported to be generally longer than the lamina. With 

 regard to the hollowness of the stem, it appears as if it often 

 extended for a greater distance. I have closely examined a large 

 example, the stem of which measnred somewhat above 2 metres, 

 and found that it was already hollow at the apex just below the 

 lamina, and this hollow expansion widened rapidly so that a few 

 inches from the apex of the stem it attained to a diameter of about 

 one inch and remained this width for a short distance; this inflated 

 part, being filled with air, serves to buoy up the lamina. When 

 growing in shallow water (1 — 2 metres), which seems to be the 

 favourite habitat of this plant, these inflated apical parts of the 

 stem may be seen in abundance floating about on the surface and 

 bearing the immense lamina which hang thence downwards towards 

 the bottom. The hollow part gradually narrows towards the base, 

 and a foot above it the stem becomes solid. In young specimens 

 the stem is solid. The haptera are long, thin, and very much divided. 



In typical, well-developed specimens the lamina is broadly el- 

 liptic, has a distinctly cordate base, a strongly waved margin, and 

 sometimes tapers somewhat to the top giving almost an ovate 

 appearance to the lamina. In young specimens the lamina is nar- 

 rower, oblong elliptic, with base less distinctly cordate, and often 

 agrees well with Harvey s figure of L. longicruris in Nereis Boreali- 

 Americ, Part 1, tab. IV and in Phycol. Brit., Vol. III, tab. 339. On 

 the other hånd, the lamina in typical, well-developed L. longicruris, 

 judging both by the specimens from Greenland and other piaces 

 preserved in the museum in Copenhagen and by the tigures and 



