170 KJELLMAN, THE ALGiE OF THE ARCTIC SEA. 



Ceramiuin rubrura (Huds.) Ag. 



Disp. Alg. p. 16. Conferva nibra Huds. Fl. Angl. p. 600. 



f. decurrens J. G. Ag. 



Spec. Alg. 2, p. 127. 

 Descr. Ceraraium riibrum a decurrens J. G. Ag. Epicr. p. 100. 

 Ewsicc. » decurrens Aresch. Alg. Scand. exsicc. N:o 208. 



f. genuina. 



f. interstitiis et juvenilibus et adultis densius corticatis; ramis lateralibus pauci.9, eonformibus, dichotomis. 



f. prolifera J. G. Ag. 



Spec. Alg. 2, p. 127. 

 Descr. Ceraraium rubrum /? proliicriim J. G. Ag. Epicr. p. 100. 

 Fig. » secundatum Lyngb. Hydr. Dan. t. .37 A. 



» botryocarpum Harv. Phyc. Brit. t. 215. 



f. 2)edicellata Duby. 



sec. J. G. Ag. Spec. Alg. 2, p. 128. 

 Descr. Ceraraium rubrum r; pedicellatum ,1. G. Ag. Epicr. p. 101. 

 Fig. » » KiJTZ. Tab. Pliyc. 1.3, t. 4, fig. a. et b. 



f. squarrosa Harv. 



Ner. Ära. 2, p. 214. 

 Descr. Ceramiiim rubrura s. squarrosura Harv. 1. c. 

 Fig. » » f. squarrosa tab. nostra 15, fig. 7. 



Syn. Ceraraium rubrum J. G. Ag. Spetsb. Alg. Progr. p. 2; Bidr. p. 11. 

 » » Croall, Fl. Disc. p. 460. 



" » GoBi, Algenfl. Weiss. Meor. p. 46. 



» » Kjellm. Spetsb. Thall. 1, p. 25; Algenv. Murm. Meer. p. 23. 



>> » Kleen, Nordl. Alg. p. 20. 



» » Nyl. et Soel. Herb. Fenn. p. 74. 



» » virgatum PosT. et Rdpr. 111. Alg. p. II. 



Conferva dinpliana Wg. Fl. Lapp. p. 511. 



Remark on the definition of tlt.e forms. Ceramium- rubrum, in the Polar Sea as well 

 as elsewhere, is multiform. The rather few specirnens frorn the former region which 

 I have had the opportunity of exaniining, appear however to be referable to the above- 

 mentioned forms. The specimens determined by me as being f. demrrens are in all 

 essential points similar to those from the northern portion of the Atlantic. This form 

 is easily knoAvn by its articular cells being at first uncorticated, by the absence of 

 prolification and by its poverty in lateral branches, which, if existing, branch in the 

 same manner as the main axis. Besides, the frond is more strongly attenuated npwards 

 than in any other form. The form designated by me as f. genuina resembles the former 

 in habit, branching etc, but differs from it by its darker colour and the strongly 

 corticated articular cells. Nearest this there stånds a robust and large-sized form, well 

 represented by fig. a, table 4 in Kutzing's Tab. Phyc. 13 and certainly belonging to 

 the same series of forms of Ceranmim. riihrmn as the plant figured pl. 181 in Harv. 



