480 



the receptacles being often more irregularly formed and sometimes 



swollen, and the colour of the plant being of a paler yellow. 



It was found bearing young receptacles in April and May, and 



the receptacles reached their highest degree of development (1— 172 



metres long) during summer, and contained ripe oogonia from July to 



September. Kjellman (l.c. p. 194) says that according toWahlen- 



berg H. lorea is not to be found during winter in Lapland which 



does not agree with what happens along the Færoese coasts. Here 



according to my observations the plant is »hapaxanthic«. I think 



the oogonia germinate immediately in autumn and develop during 



winter into the well-known button -shaped piants which are often 



ovately swollen. In my experience the latter can live several years 



without fructifying, and this appears to be more particularly the 



case when growing nearer high-water mark than is natural to the 



plant. It is undoubtedly necessary for the young plant to attain 



to a certain size and vigour in order to be able to bear fruit; those 



growing in favourable habitats probably arrive at perfection during 



the winter, others which are less fortunate keep on living for several 



years and such older piants are easily recognizable by their darker 



colour and their more leathery consistency as also by the numerous 



epiphytes which gradually occur on them. Some of these older 



piants are perhaps able to fructify later on, others, growing in the 



most unfavourable habitats, are never able to do so and eventually 



die. When the plant has fructified it dies away gradually, but the 



conical lower part and a portion of the receptacles can keep fresh 



doubtless for several years and form a favourite habitat especially for 



species of Ectocarpus, but they can hardly produce new receptacles. 



This is an extremely common species of the Færoese coasts as was 

 reported by Lyngbye, who writes: — »Ad insulas Færoenses copiose, 

 non solum in fundo, sed etiam in summo refluxus limite«. This species 

 was first mentioned by Landt, l.c. p. 228. 



C. Chlorophyceae. 



Order PLEUROCOCCOCEAE. 



PLEUROCOCCUS Menegh. 



157. PI. spec. Palmella adnata Lyngb.,Hydrophyt.,p.205,tab.69A. 



On examining Lyngbye's specimens of Palmella adnata which 



are preserved in his herbarium in Copenhagen they proved to be 



