Herposipbonia of Tropical Pacific — Hollenberg 
551 
8-10-(12) pericentral cells and composed of 
segments about 1 diameter long, attached by uni- 
cellular rhizoids arising at irregular intervals, 
mostly one per segment and having mostly digi- 
tate tips ; indeterminate branches arising on 
alternate sides of prostrate axes at intervals of 
3-5 segments, with a single determinate branch 
between successive indeterminate branches, and 
with the latter always one node distal to the 
former; determinate branches normally simple, 
60-90- (140) |x in diameter, composed of (30)- 
60-80- (100) segments, which are mostly about 
1.5 diameters long in median parts, and which 
have mostly 12-14 pericentral cells, but may 
have as few as 8 or as many as 16; central cell 
at least twice as wide as the pericentral cells; 
determinate branches usually gradually nar- 
rowed at the base and gradually or abruptly 
narrowed at the apex; chromatophores usually 
not zonate; trichoblasts 3— 5— (8), up to 2 mm 
long, with about 7 forks, arising somewhat dis- 
tichously, at decreasing intervals of 8 segments 
to 1 segment, mostly 1—2 being present at one 
time; scar-cells relatively large; tetrasporangia 
in long series of 20-30 in the terminal parts of 
the branches, slightly distending the segments; 
spermatangial stichidia lanceolate-arcuate, 400- 
560|i long, 50-SQ|i broad at the base; with a 
sterile tip of 1-2 short cells, up to 6 or more 
stichidia arising in acropetal sucession at inter- 
vals of 6-1 segments at the apices of the 
branches ; procarps and cystocarps not observed. 
Algae praesertim saxicolae, caespitem penicillosve 
amplos usque ad 1.5 cm alt. formantes; rami prostrati 
100-1 70- (200) p diam., cellulas peri centrales plerum- 
que c. 10 habentes, et e segmentis circa aeque longis 
ac latis compositi; rami indeterminati in latibus alter- 
nis ramorum prostratorum, intervallis 3—4— ( 5 ) seg- 
mentis, orientes, unico ramo determinate inter ramos 
indeterminatos successivos sito, ramo determinate in 
nodo qui distaliter ramum indeterminatum admodum 
praecedit semper sito; rami determinati normaliter 
simplices, 60-90- (1 40 )p diam., e 60-80- (100) seg- 
mentis compositi, segmentis c. 1.5 plo longioribus 
quam latis, et plerumque 12-14 cellulas pericentrales 
diametro c. dimida pars cellulae centralis habentibus; 
chromatophora non zonata; trichoblastae 3-5-(8), 
usque ad 2 mm long., 7-(9) f ureas habentes, et in- 
tervallis decrescentibus 8 ad 1 segmenta, saepissime 
1-3 semel subdistiche orientes; cellulaecicatrices mag- 
nae; tetrasporangia in partibus terminalibus ramorum 
determinatorum 20-30 seriatim disposita, segmenta 
paululum distentia; stichidia spermatangialia lanceo- 
lato-arcuata, 400-560 X 50-gQfx, cacumen sterile ex 
1-2 celiulis brevibus constans habentia; usque ad 6 
stichidia in successione acropetali, intervallis 6-1 
segmentis ad apices ramorum determinatorum, or- 
ientia; cystocarpi ignoti. 
TYPE collection: D. 22396, tetrasporic, on 
basalt shore, intertidal, near Maalaea, Maui, 
legit H., T., and B., April 19, 1965. This col- 
lection is represented by a glucose slide mount 
and fluid-preserved material. 
ADDITIONAL COLLECTIONS EXAMINED: HA- 
WAIIAN ISLANDS — T. 934A, coral reef, Trig I., 
French Frigate Shoal, legit C. R. Long, Sept. 
27, 1964; T. 581, beach drift, northeast side of 
Laysan I., Dec. 7, 1963; D. 12699.1, in inter- 
tidal reef pockets, Hanauma Bay, Oahu, Jan. 
15, 1962; H. 66-6, basalt ledge, northwest 
shelf, Hanauma Bay, Oahu, Sept. 16, 1966 ; col- 
lections by G. F. Papenfuss, Hanauma Bay, 
Oahu, Dec. 15, 1940, and Mar. 1, 1942 ; a col- 
lection by Gary Collins, no. 121, Wawamalu 
Beach, Oahu, Feb. 28, 1965; D. 22409.1, in 
algal turf, north of Papawai Point, Maui, legit 
H., T., and B., Apr. 19, 1965; D. 22503, Pene 
Beach Park, Honolua, Maui, legit H., T., and 
B., Apr. 20, 1965; D. 13458.1, on basalt ledge, 
west lip of Pohoiki Bay, island of Hawaii, Nov. 
10, 1956; johnston island — T. 1234, on 
dead coral, legit Earl Murchison, Aug. 20, 1965 ; 
line islands — L. 2708.2, tetrasporic, turf on 
rocks near breakers, southwest reef, Jarvis I., 
Nov. 16, 1964; tuamotu archipelago — D. 
11215.1, D. 11217B,C, on coral and on wood 
stump at a depth of about 5 ft, near the lagoon 
transect, Ngarumaoa, Raroia Atoll, legit M. S. 
Doty and Jan Newhouse, July 1 6, 1952; phoe- 
nix islands — L. 2534.5, west side of lagoon, 
Gardiner L, Oct. 23, 1964; American samoa 
— T. 752, on wave-washed basalt, Vatia Bay, 
Tutuila, legit R. Buggeln, Aug. 1964; gilbert 
islands — D. 18900 (Lophosiphonia obscura of 
Tsuda, 1964), in shallow passage between the 
ocean and the lagoon, Abemmama L, legit M. 
J. Cooper, July 1962; marshall islands — G. 
612.1, tetrasporic, and G. 6 13, at a depth of 19 
m, lagoon, Eniwetok Atoll, Sept. 6, 1955 ; H. 
48-0290.1, on Dictyosphaeria sp., and Eucheuma 
sp., inner reef, Eric I., Bikini Atoll, July 13, 
1948; H. 48-0914.1, tetrasporic, on Eucheuma 
sp., H. 48-0914.21, on Pocockiella sp., and H. 
