Polysiphonia of the Tropical Pacific, I — Hollenberg 
65 
P. mollis) on Rhizophora roots, Coconut Island 
Laboratory, Kaneohe Bay, Oahu, June 22, 1961 ; 
D. 19885.2-19886, abundant on rocks east of 
Kolo wharf, Punakou, Molokai, Dec 31, 1953; 
phoenix islands — Degener 24867a, tetra- 
sporic, Canton I., date?; marshall islands — 
Da. 12683, 12729, Uliga I., Mariuro Atoll, 
Oct. 12, 1954; H. 48-1213.26, on Pocockiella, 
Bikini I., Bikini Atoll, July 7, 1948; H. 
48-Y44.1, on Microdictyon, Bogen I., Eniwetok 
Atoll, July 25, 1948; H. 48-Y71, on Micro- 
dictyon, Runit I., Eniwetok Atoll, July 27, 1948. 
P. flaccidissima var. decimera var. nov. 1 
Fig. 12 
Minute algae, to barely 2 mm high from 
creeping branches to 55p in diameter and with 
segments one diameter long or mostly shorter; 
erect branches similar with lateral branches 
commonly at intervals of 10 segments; tricho- 
blasts 400-500p long with 3-5 dichotomies, 
tapering to delicate apices, scar-cells large (to 
10(i in diameter). 
Algae minutae, usque ad vix 2 mm alt., e ramis 
repentibus ad 55p, diam., segmentis aeque longis ac 
latis aut plerumque brevioribus, enascentes; rami 
erecti repentibus similes, ramos laterales intervallis 
10 segmentorum plerumque habentes; trichoblastae 
400-500(1 long., 3-5 dichotomias habentes, ad apices 
delicatos attenuatae; cellulae-cicatrices magnae (ad 
lOp diam.). 
type: H. 6 5-82, sterile, growing on dead 
coral at a depth of 1-2 m, 20 m shoreward 
from the outer reef margin, north of North I., 
Johnston I., legit R. S. Jones, Apr. 22, 1965. 
One additional collection, H. 65-85.1, on 
Pocockiella, Diamond Head Beach, Oahu, Ha- 
waii, was made by Mitsuo Kajimura, May 
4, 1965. 
The diminutive size and the strong tendency 
for branches to arise at intervals of 10 segments 
are the distinctive features. 
P. flaccidissima var. iki var. nov. 
Figs. 1G, 2C 
Minute, epiphytic algae, mostly less than 
1 cm high, from a basal attachment with little 
or no prostrate portion; main branches 50-75 p 
in diameter ; lateral branches few, at intervals 
of 4-6-(12) segments; scar-cells small but 
often pigmented; tetrasporangia 40-5 Op in 
diameter, in short, slightly spiral series; sper- 
matangial branches 1 l6-190p X 36— 40p with 
a short sterile tip of 1-2 cells; cystocarps seen 
were immature. 
Algae minutae, epiphyticae, plerumque breviores 
quam 1 cm, ex affixione basali enascentes, parte pro- 
strata minima vel nulla; rami principales 5 0—7 5 (li 
diam.; rami laterales intervallis 4-6-( 12) segmen- 
torum enascentes; cellulae-cicatrices parvae, saepe, 
autem, coloratae; tetrasporangia 40-50p diam., in 
serie brevi paululum spirali; rami spermatangiales 
ll6-190|ii X 36-40p, cacumen breve sterile ex 1-2 
cellulis compositum habentes; cystocarpi visi immaturi. 
type: D. 19145M1, tetrasporic, dredged 
6-14 fa, Port Allen, Kauai, Hawaii, Sept. 12, 
1959, is represented by a glucose mount. Addi- 
tional material studied, all from the Hawaiian 
Islands: D. 19118C2, cystocarpic, on Sargassum 
sp., dredged 16-25 fa, Pokai Bay, Oahu, Aug. 
1, 1959; D. 19144J1 and 19144Q1, spermatan- 
gial, on Liagora sp., dredged 6-14 fa, along 
with the type. 
This variety is named for its minute size 
(iki is the Hawaiian word for tiny). Other- 
wise it has the features of the species. 
P. flaccidissima var. lopi var. nov. 
Figs. 1 H, 2 B 
To 7.5 mm high from prostrate branches 
40-5 Op in diameter; erect branches 30-45- 
(60)p in diameter, of segments mostly 2 
diameters long or longer, sparsely branched 
with 10-20- (30) segments between successive 
branches, which are gradually narrowed at the 
base ; trichoblasts mostly short with 1 dichotomy, 
occasionally to 275p long composed of 3-4 
very long cells 3. 5-4. Op in diameter and rela- 
tively uniform in diameter throughout their 
length; mature reproductive structures not ob- 
served. 
Plantae ad 7.5 mm alt., e ramis prostratis 40-50p 
diam. enascentes; rami erecti 30-45 (i diam. constantes 
e segmentis plerumque 2 plo longioribus vel plus 
quam lata, sparse ramosi, 10-20- (30) segmentis inter 
ramos successivos, ad basim gradatim angustatos; tri- 
choblastae plerumque breves, unam dichotomiam 
habentes, interdum ad 275p, long., e 3-4 cellulis lon- 
gissimis 3. 5-4. Op, diam. compositae, relative uni- 
formes diametro per longitudinem; structurae repro- 
ductivae maturae non observatae. 
type: D. 10821, tetrasporic, cystocarpic, on 
a boat, just below the water line, Kaneohe Bay, 
