71 



monostromatic frond, more frequently however at the border, where the cells are 

 therefore a little smaller and closer together. The intensive marginal growth 

 results in the margin becoming much undulated. In fig. 9 C, which was drawn 

 after a dried specimen, the cells are seen to be arranged in groups of two or four 

 or a little more, rather distant from each other. 



As said above, the reproduction has hitherto been unknown in this species, 

 and I have also searched in vain for an}' indication of a fructification in several 

 fully developed specimens. In other cases, however, I succeeded in finding a for- 

 mation of spores corresponding to that in Eri]throtrichia\ even in very small spec- 

 imens it could be observed. Thus in fig. 9 B several cells are divided by an in- 

 clined curved wall into a roundish cell filled with protoplasmic contents, the 

 spore-mother cell, and a crescent-shaped sterile cell. The spore-mother cells are 

 scattered without order over the whole frond; even marginal cells may produce 

 them (fig. 9fi, at the summit). In fig. 10 is shown a small fragment of another, 

 larger plant where most of the cells have produced spores. As I have only exa- 

 mined the plant in preserved condition I cannot give any information of the be- 

 haviour of the sterile cell on the escape of the spore. 



The described fructification along with the peculiar develop- « 

 ment of the frond justify the establishment of this plant as the ^ ^ ^ 

 representative of a new genus. On account of the resemblance ® ^ # © 

 in appearance to the genus Porphyra I have named it Porphyropsis; & ^ 

 a diagnosis is given above. *^ 



Only found in the eastern Kattegat in 20 to 25,5 meters depth. Fig. lo. 



epiphytic on various Alga?. The largest specimens, 5 mm. high, Porphyropsis cocdnea. 



X 1 c Part of frond with spo- 



with much undulated margm, were met with at the end of July; mngia. m-.i. 

 young plants were collected in May and July. 



Localities. Ke: Fladeu, ZF, on stalks of Laminaria digitata, on Dihea ediilis and Rhodijmenia 

 palmaia a. o.; Groves Flak, VZ, on Desmarestia aciileata, Lille Mitldelgriuul, IK, on Odonthalia dentata. 



Erythrocladia gen. nov. 



Thallus horizontaliter expansus, e filis ramosis, aliis algis adfixis, radiatim 

 egredientibus, initio inter se discretis, dein in discum tenuem unistratosuni confluen- 

 tibus, constans. Crescentia filorum apicalis. Sporangia eodem modo ac in genere 

 Erythrotrichia in cellulis intercalaribus vel rarius terminalibus gignuntur. Generatio 

 sexualis adhuc ignotaK 



' Battkiis has in 1896 (Journ. of Botany Vol. 34) established a genus Colaconema, characterized 

 b}' branclied lilaments living in the cell-walls of various Algae and by monosporangia "formed from 

 portions cither of the terminal cells of the pi'incipal axes, or of short swollen 1- or few-celled lateral 

 branches, or even from a portion of a cell in the continuity of the filament. The undifferentiated por- 

 tions of the cells forming cup-like bases for the sporangia". This genus was later placed by Batters 

 (.Journ. of Bot. Vol. 40, 1902, Supplement p. 57) near to the genus Acrochcetiuin {Chantransia) and one 

 species was removed to this genus. The indicated mode of formation of the monosporangia suggests 

 however that the genus may include forms belonging to the Erythrotrichica', and the sporangia arising 



