65 



Localities. Ns; Nordby, Fano (C. Hascii , abinulaiitl}' in tlie FucHS-zone !) ; Esbjerg (Borgesen, dii 

 moles and embankments in tlie upper lialf of tlu- littoral region!); groins by Thyboron (in spring chielly 

 f. Unearix, in summer only broader forms. — Sk: Hirshals (on tlie mole and on boulders on tbe sbore, 

 in spring {.linearis abundantly above bigli-water mark, in summer the species disappears entirely or 

 almost entirely). Lf: Harbours of Lemvig, Struer and Thisted; Aalborg, liai'bour and piers of bridge 

 (!, Tb. Mortensen and unknown collector in herb. C. Rosenberg); Nerre Sundby; Hals. — Kn: Harbour of 

 Skagen ; Busserev (with Bangia near high-water level, small specimens in April; harbour of Frederiks- 

 havn (in winter f. linearis abundantly, mainh' at high-water level, in summer only broader forms, as 

 a rule in small quantity); harbour of Steby. — Ks: Harbour of Grenaa. ~ Sa: Kyholm (upper Fucus- 

 zone, with Ralfsia); Aarhus, liarbour, and on boulders on tiie shore bj' Riis Skov. — Lb: Harbour of 

 Bogense (I, Borgs.); Fredericia (Hofm. lig., .lob. Lange, !); Strib; harbour of Middelfart (Hofm. Bg., C. Ro- 

 senb.,!), Kongebro. — Sb: Harbour of Lohals ; Smorstakken. — Sli: Harbour of Helsinger. 



2. Porpliyra leucosticta Thuret. (Plate II fig. 4— 13.) 



Thuret in Le Jolis, Alg. mar. de Clierb. 1864, p. 100. Janczewski, Ann. sc. nat. V'' ser. t. 17, 1873, p. 241 



pi. 19 fig. 1 — 14. Berthold (1881) p. 79. Id. (1882) Taf. 1 Fig. 1-6. 

 Porphijra airopurpnrea Olivi in Saggi Accad. di Padova III. 1. 1791, teste De-Toni, Syll. Alg. IV. Sect. 1, p. 17. 

 Exsicc. : Crouan Alg. mar. du Finistere No. 397. Le Jolis Alg. mar. de Cherbourg No. 156. 



This species which has only heen met with on our most northern shores, 

 occurs there in its typical shape but does not attain a considerable size. The 

 lai'gest observed specimens are (in a dried 

 state) 10 — 11 cm. long, only one specimen was 

 16 cm. long. The longest fronds are lingulate, 

 about 2 — 4 cm. broad, with rounded or more 

 frequently cordate base, but very often the 

 margins of the frond overlap each other below 

 the base, particularly in the broadest speci- 

 mens, in which the attachment may then 

 become apparently umbilicate. The frond is 

 generally entire, rarely a little lobed, the 

 margin more or less undulated. The colour is as a rule a little more reddish than 

 in P. umbilicalis, but the difference is not absolute; the two species can occur with 

 exactly the same colour. The thickness of the frond I found to vary between 

 28 and 44 



The specimens met with in April were all provided with sexual organs, in 

 so far as they had attained a tolerable size. The antheridia formed the well 

 known patches, running longitudinally in the upper part of the frond, 5 — 10 mm. 

 long, 1 — 1,5 mm. broad. There are, however, also very small antheridial patches, 

 originating in a group of very few mother-cells. The number of spermatia arising 

 from each mother-cell is fairly often smaller than 64. As shown by Janczewski 

 (1. c. p. 247), isolated cystocarps are often scattered among the antheridia. The 

 carpogonia had very often produced a hyaline protuberance at each extremity, a 

 state which, according to Bekthold, is due to the fact that the carpogonia have 

 been obliged to wait a long time for fecundation. When all the carpogonia assume 

 this form, the frond becomes papillose on both sides. Fig. 7 B shows a spermalium 



Fig. 7. 



Porplii/ru Icucosticta. Transverse sections of Iroiid 

 with carpogonia; in A these are not fertilized, 

 while in B three of them are fertilized and two 

 (livifled by a cross-wall. :i9n:l. 



I). K, I) Viilensli, Sel.sli. Slii., 7. Hiulike, iiMtiii vidensk. ok jiiiitliem. AM. VII. 1. 



9 



