MARINE ALGM OF BEAUFORT, N. C. 465 



filament, soon developing into a flat membrane consisting of one or two cell layers; 

 propagation and reproduction as in Bangia; spore fruit consisting of eight or more cells. 



About 20 species, all marine, many of them not sharply separated. 

 Porphyra leucosticta Thuret. 



Porphyra leucosticta, Thuret, in Le Jolis, 1863, p. 100. 

 Porphyra atropurpurea, De Toni, 1897, P. 17. 

 P. B.-A. No. 376. 



Frond shortly stipitate, attached by a basal disk, consisting of a single layer of cells (except during 

 reproduction), variable in color from pink or red to purple and in form from indefinite sheets to narrow 

 bands, simple or variously divided, 2 to 40 cm. long, 0.5 to 14 cm. wide; monoecious, antheridia forming 

 small, elongated, colorless patches among the darker female organs. 



Temperate North Atlantic and Pacific; Mediterranean. 



Very abundant between tide lines throughout harbor and on jetties, Beaufort, N. C., January to 

 May. 



At Beaufort the plants are kidney shaped to linear, lanceolate and laciniate, 3 to 10 cm. long, of a 

 pinkish or brownish purple color. 



Another species, P. laciniata (Lightf.) Ag. has not been observed in this region, but 

 may be found here at times, although it is, in general, a more northern form than 

 P. leucosticta. These species can not be separated by form or color, but are distinguished 

 as follows: P. leucosticta, monoecious, antheridia occurring in small, elongated, colorless 

 patches; P. laciniata, usually dioecious, antheridia forming a colorless marginal zone. 



Genus 3. Goniotrichum Kuetzing. 



Goniotrichum, Kuetzing, 1843, p. 244 (in part). 



Thallus erect, filamentous, consisting of a single row of cells, exhibiting "false 

 branching," or, occasionally, laterally branched; cells rose colored, containing single, 

 star-shaped chromatophores and single nuclei; cell walls soon becoming gelatinous; 

 asexual propagation by transformation of vegetative cells into monosporangia, their 

 contents soon escaping as naked monospores; sexual reproduction unknown. 



Two species recognized. 



The members of this genus are peculiar in combining characters of the blue-green 

 and the red algae. In their possession of "false branching" and gelatinous sheaths 

 formed by the swelling of the cell walls inclosing the filaments, they resemble the Myxo- 

 phyceae, while the structure of their cells, and especially their method of propagation, 

 place them among the Bangiaceae in the Rhodophyceae. 



Goniotrichum alsidii (Zanardini) Howe. Fig. 23. 



Bangia alsidii, Zanardini, 1839, p. 136. 

 Goniotrichum elegant, Zanardini, 1847, p. 254 (69). 

 Goniotrichum elegans, Forti, in De Toni, 1907, p. 687. 

 Goniotrichum elegans, Tilden, 1910, p. 295. 

 Goniolrichum alsidii, Howe, 19143, p. 75. 

 P. B.-A. No. 781. 



Filaments red, i to 5 mm. long, inclosed in gelatinous sheaths; cells cylindrical or elliptical, 7 to 

 10 mic. wide, n to 20 mic. long; sheaths 2 to 6 mic. wide on each side of filament, often with crenate 

 edges. 



Warm and temperate North Atlantic. 



Occasional on other algae and on eel grass (Zoster a marina), usually occurring in very small quan- 

 tities, abundant on one old specimen of Padina vickersia, Fort Macon jetty, December, 1908, and occa- 

 sional on various algae dredged from coral reef offshore, Beaufort, N. C., August, 1914 and 1915. 



