Contribution. I. 



59 



f, typica. 



Beser. Porphyra laciniata Thur. in Le Jol. Liste Alg. Cherb. p. 100. 



Harv. Phyc. Brit. t. 92. 

 Arescli. Alg. Scand. exsicc. Nr. 116, 312. 

 var. elon^ata Åresch 1. c. Kr. 117. 



Fig. 



JExsicc. 



n 



« 



?) 



vulgaris Aresch. 1. c. Nr. 261. 



f. umhilicalis L. (Kleen.) 



Nordi. Alg. p. 23; Ulva umbilicalis L. Spee. Pl. 2, p. 1163. 

 Descr. Ulva umbilicalis Lyiigb. Hydr. Ban. p. 28. 

 Exsicc. Porpliyra laciniata f. h. Aresoh. Alg. Scand. exsicc. Nr. 260. 



Sm. Ulva umbilicalis Gunn. Fl. Norv. 2, p. 121. 



ff 



» 



Wg. FL Lapp. p. 506; excl. var. 



This.species is also at East-Finmarken much varying, 

 appearing in a rather large nnmber of forms. I have not 

 succeeded in drawing any limits between thera, with excep- 

 tion of f. iimUlicaUs, which is a well difPerentiated form. 

 The specimens distribnted in Aresclioug Alg. Scand. 

 exsicc. 1. c. will show sorae of the forms that I mean by f. 

 hjpica, or have referred to this form. It varies as to the 

 colonr by dried specimens between light flesh-coloured and 

 amethystine. The thickness of the frond is generally 30— 40 

 p-, bnt I have coUected specimens which were, at the middle, 

 60 ^ tbick. The difFerence seems chiefly to befoundedupon 

 the conditions at the places wliere the plant is growing. In 

 the inner part of deep bays it becomes seldom lobed, but 

 We it often reaches a considerable size. Thus I have seen 

 specimens at Russemarlc (Porsangerfjord) in West-Mnmarken, 

 ^^eing in general perfectly simple and attaining a length of 

 ^ raetre by a breadth of 0.5 m. and more. 



The typical form is litoral or sublitoral. 



former 



case it grows mostly scattered, attached to rocks or other 

 algæ, as Ilalosaccion ramcntoccum, JDumontia filiformiSy Rho- 

 dymcnia palmafa etc. In the latter case I have only met with 

 it fastened to other alga^, for inst. Lithofhamnia, PHlgta mi 



Lmimrn- It desoendK^i to e\> depth of about Sfathoms, ThQ 



1 



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