204 
PACIFIC SCIENCE, Vol. XXII, April 1968 
Menez, July 26, 1958; EAST indies (Siboga Ex- 
pedition collections loaned from Rijksher- 
barium, Leiden, and identified by Mme. Weber 
v. Bosse as Lophosiphonia obscura ) — Sta. 14, 
Kangean I., east of Java, Mar. 14, 1899; Sta. 
165, Fausses Pisangs I., west of New Guinea, 
Aug. 20-22, 1899; Sta. 277, Dammer I., east of 
Timor, Jan. 9-11, 1900; Sta. 296, coast of 
Timor, Jan. 24-26, 1900; Singapore — D. 
1642 5 A, on mangrove stems and roots at sea 
edge of mangrove swamp near Caltex refinery, 
Paudan Nature Reserve, Nov. 31, 1957; Cey- 
lon — W. Ferguson, Ceylon Algae 239 (as 
Lophosiphonia obscura ), Rijksherbarium. 
The wide distribution of P . howei in the 
Atlantic and Pacific Oceans was previously re- 
ported by Hollenberg (1958:64). The present 
study extends the distribution westward to the 
Indian Ocean and shows that this species is 
common throughout the tropical Pacific. Fur- 
thermore, a collection by J. Feldmann at Roscoff, 
France, Aug. 25, 1946, is probably to be iden- 
tified with this species. Erect branches arise in 
the characteristic exogenous manner from pros- 
trate branches, and the specimens exhibit most 
of the detailed features of the species, although 
the rhizoids arise from the middle of the peri- 
central cells instead of from the distal end. 
Hence it seems probable that P. howei occurs 
also in southern Europe. 
Polysiphonia pentamera sp. nov. 
P. fragilis Tsuda 1964:11, not of Suringar 
1870:37. P. mollis? Weber v. Bosse 
(1923:356) (in part), not of Hooker and 
Harvey. 
Fig. 2D 
Plants epiphytic with prostrate branches 2-3 
cm long and (115)-175-200p in diameter, and 
with segments mostly shorter than their diam- 
eter, attached by unicellular rhizoids which are 
cut off from the pericentral cells by a cross-wall; 
assurgent erect branches to 3.5 cm high of a 
similar diameter and with segments about 1 
diameter long in older parts and very short in 
younger terminal parts; branching mostly 
exogenous, sometimes cicatrigenous, pseudo- 
dichotomous and occasionally somewhat dis- 
tichous, at relatively wide angles and at intervals 
of (6) -12-2 5 segments, the branches not con- 
stricted at the base, arising in connection with 
trichoblasts; pericentral cells 5, ecorticate; walls 
hyaline, firm, and of moderate thickness, mostly 
but little constricted at the clear dissepiments; 
trichoblasts mostly at intervals of 12-14 or more 
segments, with 3-4 dichotomies, quickly de- 
ciduous, leaving small scar-cells; tetrasporangia 
about 55p in diameter in very long, slightly 
spiralling series up to 60 or 70 in the upper 
branches; sexual reproduction unknown. 
Plantae epiphyticae, ramos prostratos 2-3 cm long, 
et (115) — 17 5 — 200pi diam., segmentis plerumque brevi- 
oribus quam lata habentes; per rhizoidea unicellularia 
quae a cellulis pericentralibus per dissepimentum sep- 
arantur affixae; rami erecti assurgentes ad 3.5 cm alt., 
ramis prostratis diametro similes, segmenta in parti- 
bus vetustioribus aeque longa ac lata et in partibus 
iuvenibus terminalibus brevissima habentes; rami 
plerumque exogeni interdum cicatrigene, pseudo- 
dichotomi et interdum satis distichi, angulis relative 
latis, intervallis (6)-12-25 segmentorum, ramis ad 
basim non constrictis, in associatione cum trichoblastis 
enascentibus; cellulae pericentrales 5, ecorticatae; 
parietes hyalini firmi satis crassi, ad dissepimenta 
manifesta saepissime vix constricti; trichoblastae pler- 
umque intervallis 12-14 vel plurim segmentorum dis- 
positae, 3-4 dichotomias habentes, cito deciduae, 
cellulas-cicatrices parvas relinquentes; tetrasporang : a 
ca. 55u diam. 60-70 in serie longissima subspirali in 
ramis superioribus ; reproductio sexualis ignota. 
type: G. 524.2, tetrasporic, from a depth of 
28 m, in the lagoon, Eniwetok Atoll, Aug. 30, 
1955. 
ADDITIONAL COLLECTIONS: HAWAIIAN IS- 
LANDS — D. 19135W2, on other algae, dredged 
26 fa, Waialua, Oahu, Aug. 2, 1959; gilbert 
islands — D. 18937 A, from a coral reef, Mara- | 
kei I., legit M. J. Cooper, July, 1962, and iden- ! 
tified by Tsuda (1964:11) as P. fragilis Surin- ! 
gar; Caroline islands — D. 21223.1, tetra- 
sporic, creeping on a Padina sp., on a reef flat j 
near the bridge between Kolonia and Jokai I., 
Ponape Group (6°58'N, 158°11'E), legit E. 
Menez, June 25, I960; east indies — two col- 
lections made on the Siboga Expedition and 
identified by Weber v. Bosse (1923) as P. mol- 
lis? Hooker and Harvey; Sta. 77, on other algae 
dredged 40-60 m, Borneo Bank, southeast of 
Borneo, June 12, 1899; Sta. 133, Lirung, Sali- 
babu I., "flottant le long du bateau,” July 
25-27, 1899; Vietnam— Da. 11277, tetra- 
sporic, as P. fragilis Suringar, lie de Tre; Da. 
11278A, tetrasporic, as (P. coacta Tseng) from 
Nhatrong, Feb. 16, 1952. 
