151 



EXPLANATION OF PLATES. 



All li^Lires iiro photographs alter dried specimens, about 'Ir, nat. size. 



Plate I. 



Por]>hi]ra nmhilicalis (L.) .1. Ag. 



1. Monoecious specimen showing a longitudinal limiting line between Ihe male and the lemale 

 part of the frond. (Ilclsingor, September). 



2. Small male sj)ecimen {(. lacinialn); the mai'ginal zone has produced antheridia. Helsingor, 

 September). 



3. Female plant. The fertile zone above shows irregularly ramified spots caused b}' earlier 

 maturation of the cystocarps here than in the surrounding parts. (Norre Sundby, Lim- 

 fjorden, September). 



Plate II. 



1—3. Porpbijra iiinbilicalis (L.) J. Ag. f. linearis (Grev. . 1, monoecious, 2, female, 3, male specimen 

 (Frederikshavn, December— January). 



4—13. Porphyra leiicosticta Thur. 



4—7. Sexual plants, (harbour of Skagen, April 1905, M. L. Mortensen). 



8. Asexual jjlant, possibly producing gonidia, (harbour of Skagen, July 1907). 

 9—13. Small specimens being the under part of specimens which have exhausted their spcr- 

 matia and carpospores, (harbour of Skagen, July 1905). 



