MARINE ALGJB OF BEAUFORT, N. C. 443 



Genus i . Petalonia Derbes and Solier. 



Petalonia, Derbes and Solier, 1850, p. 265. 

 Phyllitis, Farlow, 1882, p. 62. 

 Phyllitis, De Toni, 1895, P- 487. 



Frond leaflike, without veins, usually band shaped, less often linear or filiform, 

 tapering toward the base to a short, filiform stipe, occasionally fistulose; interior 

 structure composed of larger cells intermixed with slender, segmented filaments, outer 

 layer composed of smaller cells; sometimes hollow; paraph yses lacking; fertile regions 

 at first as sori, then occupying nearly the entire surface of the frond ; sporangia external, 

 bound together, at least at first, into a tissuelike mass; " plurilocular sporangia" subcy- 

 lindrical; "unilocular sporangia" insufficiently known. 



Three species, in cold and temperate seas. 



Petalonia fascia (Mueller) Kuntze. PI. LXXXVI, fig. i. 



Fucus fascia, Mueller, in Flora Danica, pi. 768. 



Laminaria fascia, Harvey, 1852, p. 91. 



PhyUitis fascia, Farlow, 1882, p. 62. 



Phyllitis fascia, De Toni, 1895, p. 487. 



Petalonia fascia, Kuntze, 1898, p. 419. 



A. A. B. Ex. No. 199 (PhyUitis fascia). 



P. B.-A. Nos. 276. 736, 1131 (PhyUitis fascia). No. 1082 (Petalonia zosttri folia). 



Frond extremely various in size and form, up to 30 cm. tall, i to 55 mm. broad, tapering cuneately 

 below into a stipe springing from a shieldlike attachment, simple or branched. 



Cold and temperate seas generally. 



Abundant on rocks of Fort Macon and Shackleford jetties, less abundant in harbor, Beaufort, N. C. f 

 December to April, 1908 and 1909. 



This species was not collected in November and seems to disappear entirely by May. 



Genus 2. Rosen vingea Borgesen. 



Rosenvingea, Borgesen, 1914, p. 178 (22). 



Frond tubular, cylindrical, or slightly compressed, attached by a rootlike disk, 

 branched, branches scattered or pseudodichotomous; growth intercalary by division of 

 the cells of the entire frond ; wall composed of 3 to 4 layers of cells, external ones small, 

 becoming larger toward the cavity, peripheral cells containing single, disk -shaped 

 chromatophores ; hairs single or many aggregated, scattered over the entire frond, 

 occurring either in the sori or on sterile portions of the frond; "plurilocular sporangia" 

 subcylindrical or club-shaped, arising from the division of the cortical cells, occurring 

 in sori forming very irregular spots scattered over the entire surface of the frond. 



Four species in warm and temperate seas. 



Rosenvingea orientalis (J. Agardh) Borgesen. PI. LXXXVI, fig. 2. 



Asperococcus orientalis, J. Agardh, 1848, p. 78. 

 Asperococcus orientalis, De Toni, 1895, p. 495. 

 Rosemiingea orientalis, Borgesen, 1914, p. 182 (26). 

 P. B.-A. No. 1640 (Asperococcus orientalis). 



Frond tubular, light yellow-brown; 10 to 40 cm. long, i to 2 mm. diameter, dichotomous or vaguely 

 branched, here and there constricted and twisted; branches usually tapering at base and apex, 

 repeatedly dichotomous. 



Warm waters of Atlantic, Pacific, and Indian Oceans. 



