190 KJELLMAN, THE ALG^E OF THE AKCTIC SEA. 



withiii the Laininariaccte-formatioii. Most of the Greenland specinieiis are collected in 

 March and April, sotnc in October, whicli seenis to indicate tliat the plant is to be 

 found liere all the year round. Judging froui these specimens it also bears repro- 

 ductive organs at dificrent seasons. 



Geogr. Distrib. Its maximum of frequency is no doubt in Baffin Bay. Besides, it 

 has been observed in the eastern part of the Greenland Sea. The northernmost locality 

 where it is at present known to grow, is Fairhaven, on the uorth-west coast of Spitz- 

 bergen, Lat. N. 79° 49'. 



Localities: The Greenland Sea: the north-west coast of Spitzbergen, rare. 



Baffin Bay: Kakertok, Tessarmiut Bay, Kangek (near the same bay), Julianeshaab, 

 Egedesminde, Godthaab. If the P. vnUjaris of Ckoall and Dickie is the present species, 

 as I think it is, D. ndnatum, is known also from Disco Bay and Whale Sound. 



Gen. Porphyra Ag. 



Syst. Alg. p. XXXII. 



Porphyra laciniata (LiGfiTF.) Ag. 



1. o. p. 190. Ulva laciniata Ligiitf. Fl. Scot. p. 974. 



f. typica. 



Descr. Porphyra laciniata Tnuii. iu Le Jol. Liste Alg. Chcrl). p. 100 — 101. 



Fig. » » Harv. Phyc. Brit. t. 92. 



Exsicc. » » AiiEscH. Alg. Scand. exsicc. N:o 116. 



f. umhilicalis (L.) Kleen. 



Nordl. Alg. p. 23. Ulva umbilicalis L. Spec. Pl. 2, p. 1163. 

 Descr. ¥lva umbilicalis Lyngb. Hydr. Dan. p. 28. 

 Exsicc. Porphyra laciniata I", b. Aresch. Alg. Scand. exsicc. N:o 260. 

 Syn. Porphyra laciniata Aresch. Phyc. Scand. p. 404. 



» » GoBi, Algenfl. Weiss. Meer. p. 50. 



» » Kleen, Nordl. Alg. p. 23; excl. var. lineari et vnlgari. 



» )) umbilicata RuPR. Alg. Och. p. 393. 



u » vulgaris Nyl. et Scel. Herb. Mus. Pann. p. 75. 



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

 » I) Wg. Fl. Lapp. p. 506; excl. var. 



Remark on the qjecies. Thuret has pointed out that what is set down by algo- 

 logical HUthors under the name of P. Hnearis, P. vulgaris or P. imrpurea, and P. laci- 

 niata, sonietimes as separate species, sometimes as forms of the same species, is in fact 

 nothing but one and the same plant at difierent stages of development; cp. Thur. 1. c. 

 This being so, the names P. Hnearis, vulgaris, and purpurea, ought to be struek out 

 altogether. The plant described under the name of Ulva umbilicalis or U. umbilicata 

 I think ought to be regarded as a special form of P. laciniata. It difiers from the 

 typical P. laciniata both biologically and morphologically, and is well known to Scandi- 



