MARINE ALG OF BEAUFORT, N. C. 447 
The species considered here seems to be the same as that discussed by Bérgesen (1914), but it may, 
perhaps, be questioned whether it is the same as Rivularia zostere Mohr or Castagnea zostere Thuret. 
Both the Beaufort and the Bermuda plants are more branched than the more northern ones called by this 
name, and seem to belong to a different species. 
The single occurrence of this species on the beach makes it probable that these plants did not grow 
in this locality, but were brought here from some other region. Since, however, it probably occurs both 
north and south of this place, it may be expected to establish itself here at any time. 
Genus 3. Leathesia Gray. 
Leathesia, Gray, 1821, p. 301. 
Frond small, at first globose and solid, at length irregularly lobate and hollow, 
gelatinous-fleshy; axis short, composed of oblong cells joined into decompound-forked 
filaments radiating from a central point; peripheral assimilating filaments short, going 
out from the outermost smaller cells, enwrapped in mucous, simple, clavate, short, 
moniliform-segmented; longitudinal growth by trarisverse division of the upper segments 
of free apical filaments, the upper divisions finally changed into assimilating filaments; 
‘“unilocular sporangia’? ellipsoid or pear shaped; “‘plurilocular sporangia” linear, 
composed of a single longitudinal series of cells; both kinds occurring at the base of 
peripheral filaments. 
Five to six species, in cold and temperate seas. 
Leathesia difformis (Linnezus) Areschoug. Pi. LX XXVIII, figs. 1 and 2. 
Tremella difformis, Linnzus, 1755, P. 429. 
Leathesia difformis, Areschoug, 1847, Dp. 376, pl. 9 B. 
Leathesia tuberiformis, Harvey, 1852, Dp. 129. 
Leathesia difformis, Farlow, 1882, p. 82, pl. 5, f. x. 
Leathesia difformis, De Toni, 1895, p. 422. 
P. B.-A. Nos. 130, 829. 
Frond subglobose, variously lobate, variable in size, about 1 to 5 cm. in diameter, olivaceous brown; 
at first solid, soon becoming hollow by the disintegration of the cells of the central axis; peripheral 
filaments clavate, the terminal cell enlarged; sporangia about 35 by 17 mic. 
Cold and temperate North Atlantic and Pacific. 
Abundant on other alge and on rocks of Fort Macon jetties, Beaufort, N. C., April, 1908, March and 
April, 1909. 
This is the most southern station reported for the species, although it may be found slightly farther 
south in the winter or spring. The species seems to make a short stay at Beaufort, not being found there 
in May, 1907, and being collected in only the two months noted during the winter and spring of 1908-9. 
The Beaufort specimens were small, having a diameter of 1 to 2 cm. 
Family 5. STILOPHORACEZ (Negeli) De Toni and Levi. 
Frond attached by a rootlike disk, filiform, more or less branched, composed of an 
axial bundle of segmented filaments increasing in length by the division of subterminal 
cells, and a parenchymatous, few-layered, cortical tissue clothing the axis; this cortical 
tissue arising from the lower cells of the segmented, subclaviform filaments springing 
from the axial bundle below its apex; frond solid when young, often becoming hollow 
with age, and traversed by branches of the axial filaments; assimilating filaments present; 
sporangia of both kinds formed as lateral branches from the base of short, simple, or 
branched filaments arising from superficial cells; ‘“unilocular sporangia’ obovate or 
club shaped; ‘‘plurilocular sporangia” linear, consisting of a single longitudinal row 
of cells. 
Five to six species in North Atlantic and Mediterranean. 
