88 MARINE ALGAt 
set at acute angles, givimg the plant a slender appearance; color black 
or dark brown. It is common on the California coast. (Plate XXVI.) 
P. Baileyi. Frond three to six inches high, flat; branches emanate 
from edges of the flat stems; main branches wide-spreading and irregularly 
placed, secondary branches regular and alternate; branchlets one eighth 
to one half of an inch long, covered on the edges and around the top 
with incurved ramuli; branchlets broken off near the base of the 
branches in mature plants; branchlets usually uniform in length, but 
occasionally one is longer and branches like the primary stem; color 
black. Common on the California coast. 
P. Harveyi. Frond two to six inches high; grows in globose tufts, 
and has a bushy aspect; branches stiff and wide-spreading; stems and 
branches beset with simple or branched spine-like branchlets ; color 
dark brown, or black when dry; does not collapse when taken from the 
water; cystocarps on short stalks ; siphons four in number. It grows 
on eel-grass and algz, and is common in Long Island Sound and north- 
ward. Called locally niggerhair. (Plate XXVI.) 
P. Olneyi (dough-balls). Fronds two to five inches high, densely 
tufted; soft filaments of hair-like fineness, much branched, and spread- 
ing; when in fruit covered with tiny balls or cystocarps; siphons four 
in number. It iscommon from Cape Cod to New York. 
P. fibrillosa. Frond four to ten inches high, rather robust below; 
main stem quickly lost in a number of prominent stems and spreading 
branches; irregularly and profusely branched, becoming ultimately very 
fine; numerous branchlets covered with colorless fibrils in hairy tufts, 
which give it a misty appearance; fibrils so delicate that they do not 
show well in dried specimens, but a distinct feature by which to recog- 
nize the species in the young plant; color light to dark brown; cysto- 
carps adherent to branchlets or on short stalks; siphons four in number ; 
main branches only corticated. It is common in summer on stones and 
on eel-grass, at low-water mark, from Cape Cod to New York. (Plate 
XXVIL.) 
P. violacea. Fronds six to twenty-four inches high, pyramidal in 
general outline; main axis with long, wide-spreading branches at the 
base; branches rather robust and naked below, but numerous and be- 
coming very fine and tufted at top; cystocarps adherent or on short 
stalks; siphons four in number; main stems corticated; ultimate 
branchlets show articulations; color brownish-red. It is common from 
New York northward. (Plate XXVII.) 
P.urceolata. Frond three to ten inches high; main stem bristle- 
like; branches naked below, divided and subdivided above; branches 
with short branchlets set at a wide angle and often recurved; siphons 
four in number; shows articulations; color deep red. Name refers to 
cystocarp, which resembles a pitcher. The plant grows in loose tufts, 
and is common from New York northward and on the California coast. 
Variety formosa. Filaments soft and finer than in P. urceolata ; 
branches long and flexuous ; articulations five to ten times longer than 
broad; color bright red. It grows in tufts sometimes a foot long, and 
is found only in the spring. 
P. variegata. Fronds four to ten inches high; filaments thick as a 
bristle below, and branched in a forking manner to the very top; 
divided at long intervals below, at the top becoming of hair-like fineness 
