206 MINNESOTA BOTANICAL STUDIES. 



Agardh (3) adopted the latter spelling and it has since been in 

 general use, although Rhodomcnia and, according to Ardis- 

 sone, Rhodhymenia and Rodkymenia also have been occasion- 

 ally employed. 



Rhodymenia pertusa was first described and figured by Pos- 

 tels and Ruprecht, p. 20, pi. j6, under the name Porphyra 

 pertusa. Kiitzing, p. 693, describes it under this name. He 

 introduces a question, however, in respect to its generic de- 

 termination. J. G. Agardh (3), p. 376, points out that the spe- 

 cies should be classed as a Rhodymenia and not as Porphyra. 

 He describes it as Rhodymenia pertusa (Post, and Rupr.) and 

 places it, together with Rhodymenia palmata (Linn. Sp. 2 : 

 1630) and Rhodymenia peruviana (J. Ag. Mscr.) in the sec- 

 tion Palmata characterized by " tetraspores occurring through- 

 out the surface of the frond, scattered or collected into sori." 

 In his Epicrisis (Agardh, J. G. (4), p. 379), he assigns it the 

 same position. 



Agardh (3) gives the habitat of Rhodymenia pertusa as " in 

 the Arctic Ocean near Kamtschatka (Mus. Petropolitani !) ; 

 and near Greenland (Wormskjold !)." Kjellman reports it 

 it from the northwest coast of Spitzbergen and the west coast of 

 Greenland. It was first reported from the northwest coast of 

 America by Harvey (i) who found it among the algae collected 

 by Captain Wilkes' exploring expedition. Harvey gives its 

 locality as the Straits of St. Juan de Fuca. He compared 

 Wilkes' specimens with an authentic specimen furnished him 

 by Dr. Ruprecht and found them identical in species, though 

 Wilkes' specimens were considerably larger than Ruprechts's. 

 Harvey, p. 171, also reports the species as collected by Dr. 

 Lyall in 1859-61, his specimens being " cast ashore on Point 

 Roberts, and on rocks at low water, Fuca Strait." Cystocarps 

 were present on both sets of specimens mentioned by Harvey. 

 In commenting on the specific name, Harvey (i) p. 148, states 

 that to him the perforations of the thallus appear to be due to 

 casualties. 



In 1893 Carruthers, p. 80, examined one of the specimens 

 mentioned by Harvey as collected by Dr. Lyall. He found 

 that in that specimen the cystocarps occur all over the much 

 perforated segments ; the majority are very young and project 

 but little from the surface of the thallus. The structure of the 

 thallus is that typical of the genus. He says " The cystocarp 



