552 
PACIFIC SCIENCE, VoL XXII, October 1968 
48-0914.17, Uku L, Bikini Atoll, July 13, 1948; 
H. 48-Y58.4, Biijiri I., Eniwetok Atoll, July 26, 
1948; gilbert islands — D. 18900, lagoon en- 
trance, eastern side of Abemmama I., legit M. J. 
Cooper, July, 1962; Caroline islands — all 
legit Ernani Menez, I960; D. 15586.5, on Pa- 
dina sp., reef at Koror L, Palau Group, Sept. 
15; D. 21709.6, D. 21710.5, on dead coral, 
D. 15676.1, on other algae, reef flat, Epelkapw 
I. , Ponape, June 20; D. 15721.1, 21739-1, on 
dead coral, on reef eastern side of Mantapeitak 
I., June 20; D. 210793, on other algae, Helen 
Reef, western Caroline Islands, Aug. 28; D. 
23 11 2.2 A, on Micro duty on sp., reef on the 
eastern side of Ifalik and Falalap Islands, Aug. 
10; D. 23207.3, among other algae, southern 
tip of Sorol L, Aug. 13; Philippine islands — 
D. 18210B, among other algae, Mawes L, Hin- 
atuan, Surigao, July 7, 1958; viet nam — E. Y. 
Dawson no. 11247, spermatangial, on coral, in 
a lagoon, Hon Mieu, Nhatrang, Feb. 3, 1953; 
maldive islands — Ha. 5-2B-1 19C-28A, Ha. 
5-2B-1 19A-52A, Ha. 5-2B-119A-53D, island 
lagoon at a depth of 1—2 ft, outer reef flat, 
southeast and south of Himmafuri I., Male 
Atoll, Mar. 21, 1964; Ha. 9-2E-121-33A, on 
Caulerpa sp., along channel sides between 
Maro and Mafilefuri, Fadiffolu Atoll, Mar. 24, 
1964; Ha. 20-2J-129-6, Ha. 20-2J-129-7, on 
a reef at a depth of 3-10 ft, Ugufaru, North 
Malosmadula Atoll, Apr. 21, 1964; Ha. 29- 
2P-11, Ha. 29-2P-12, spermatangial and Ha. 
29-2P-13, in Thalassia beds, on a small island 
south of Fedu I., Addu Atoll, May 8, 1964. 
Indeterminate branches were observed in sev- 
eral instances to develop from the upper parts 
of determinate branches in the case of L. 2708.2 
listed above. On account of the reduced number 
of pericentral cells in the plants of this collec- 
tion there is some question concerning their 
identity. 
This widely distributed and fairly common 
species exhibits considerable variability in size. 
Specimens collected in more isolated areas such 
as Johnston Island and the Marshall Islands are 
usually smaller than those on larger land masses 
such as the Hawaiian Islands and the Asiatic 
mainland. However, more slender forms occur 
also in the Hawaiian Islands. One such collec- 
tion, D. 17197A2, has determinate branches 
mostly less than lOOp in diameter, with seg- 
ments mostly not over 1 diameter long. It was 
collected from Kalapana Beach, Kaimu Bay, 
island of Hawaii, Feb. 27, 1953. Of special in- 
terest in this collection is the occurrence of a 
mature cystocarp attached at about the 8th seg- 
ment from the base of the determinate branch. 
The cystocarp is distinctly urceolate and is about 
30 Op in diameter. In view of the terminal posi- 
tion of the spermatangial stichidia of H. pa- 
cified, the position of this cystocarp would seem 
to make questionable the identity of this col- 
lection. 
Herposipbonia parca Setchell. Setchell 1926:103 
H . terminalis Segi 1954:365, nomen nudum 
Figs. 2 C, 16, 20, 22, 23 
Epiphytic algae, with prostrate indeterminate 
branches typically 100-1 3 Op in diameter, com- 
posed of segments 1.0-1. 5- (2.0) diameters 
long, with 8-10 pericentral cells and attached 
by numerous rhizoids, often with digitate or 
multicellular apices ; 3 determinate erect 
branches in regular sequence between sucessive 
indeterminate branches, typically without bare 
nodes ; determinate branches strongly arched 
when young, composed of 8-1 2- (20) seg- 
ments, mostly about 1 diameter long but often 
shorter or up to 2.5 diameters long, (40) -50- 
75— (90)p in diameter, with mostly 8-10 peri- 
central cells; chromatophores often zonate; trich- 
oblasts 2— (3), terminal, the shorter one on the 
side toward the apex of the bearing branch ; 
trichoblasts with 3-5 unequal forks and taper- 
ing to delicate tips, often rudimentary but fre- 
quently to 400p long and occasionally up to 1.2 
mm long; tetrasporangia in straight series of 
mostly 5-6 in the middle or lower segments of 
determinate branches; procarps and cystocarps 
strictly terminal, the cystocarps globular to 
slightly urceolate, up to 400p in diameter ; sper- 
matangial stichidia 2-(3), terminal, oblong at 
maturity, up to 190 X 8 ^p with a sterile tip of 
1—2— (5) cells. 
type locality: Tahiti. This is one of the 
most common species found in the central 
tropical Pacific Ocean. Examination of the type 
collection, represented by four slide mounts, 
kindly loaned by the University of California at 
Berkeley, confirmed the writer’s opinion that the 
