512 BULLETIN OF THE BUREAU OF FISHERIES. 
Callithamnion polyspermum Agardh. 
Callithamnion polyspermum, Agardh, 1828, p. 169. 
Callithamnion polyspermum, Harvey, 1853, D. 234. 
Callithamnion polyspermum, Farlow, 1882, p. 126. 
Callithamnion polyspermum, De Toni, 1903, p. 1315 
Frond capillary, forming more or less dense tufts 1 to 6 cm. tall, branching profuse, decompound, 
alternate, radial below, distichously pinnate above, pinne naked at the base, pinnulate above the 
middle; slightly corticated, segments of the main filaments 2 diameters long below, 4 diameters above, 
uppermost ones shorter; tetrasporangia numerous, secund on the inner side of the pinnules or scattered; 
cystocarps large, rotund-ovate, occurring singly or up to four or five together; texture flaccid; color 
bright, purplish rose. 
Warm and temperate North Atlantic; Vancouver Island. 
Several small tufts on Fort Macon jetty, Beaufort, N. C., June, 1907. 
Two small masses of Callithamnion collected on Fort Macon jetty at the same 
time as the above may also be referred to this species or may be specimens of C. tetra- 
gonum (Wither.) Ag. Two other specimens from Fort Macon jetty, March, 1909, 
resemble C. affine Harv., but are immature and can not be determined with reasonable 
certainty. In addition to these, many small masses or fragments insufficient for deter- 
mination have been found on Bogue Beach at different times. 
Genus 4. Spyridia Harvey. 
Spyridia, Harvey, in Hooker, 1833, p. 336. 
Frond erect, usually terete, sometimes somewhat flattened, branching profuse, 
usually radial, sometimes somewhat distichous, frond beset with numerous more or 
less fine, hairlike, persistent or somewhat evanescent branchlets composed of single 
rows of cells, sometimes with layers of cortical cells encircling the nodes or covering 
the entire branchlet; structure cellular, with a central axis composed of a row of large 
cells and surrounded, for the most part, by a more or less dense cortex whose cells become 
smaller toward the surface; tetrasporangia occurring singly or in groups externally 
at the nodes of hairlike branchlets, triangularly divided; antheridia forming more 
or less expanded cylindrical patches inclosing portions of the hairlike branchlets; 
procarps terminal on short branches, bearing two opposite auxiliary cells; cystocarps 
terminal on short lateral branches, at first having two lobes, later forming three or 
more irregular lobes, pericarp rather thick, at first closed, later opening irregularly, 
gonimoblast divided into several lobes composed of dichotomous fastigiate filaments, 
forming carpospores from their upper segments, these spores appearing in tufts 1adiating 
from a placenta that is continuous with the stalk of the cystocarp and is prolonged 
almost to its apex. 
About 17 species in warm and temperate seas. 
KEY TO SPECIES. 
Ultimate branches not markedly tapering toward the bases, not club-shaped.1. S. filamentosa (p. 512). 
Ultimate branches markedly tapering toward the bases, club-shaped..............2. S. clavata (p. 513). 
1. Spyridia filamentosa (Wulfen) Harvey. Pl. CXI, fig. 1 
Fucus filamentosus, Wulfen, 1803, p. 64. 
Spyridia filamentosa, Harvey, in Hooker, 1833, p. 336. 
Spyridia filamentosa, Harvey, 1853, p. 204. 
Spyridia filamentosa, Farlow, 1882, p. 140, pl. 10, f. 1, pl. 12, f. 2. 
Spyridia filamentosa, De Toni, 1903, p. 1427. 
A. A. B. Ex. No. 1514, b. 
P. B.-A. Nos. 393, 1746, 1897. 
