86 
PACIFIC SCIENCE, Vol. XXII, January 1968 
Algae praecipue saxicolae, relative setaceae, maculas 
amplas ad 1 cm alt. e ramis prostratis volugo for- 
mantes, per rhizoidea quae primum unicellularia et 
ut cellulae discretae plerumque ab extremo distali 
cellularum pericentralium separata, matura, autem, 
cacumina multicellularia plerumque efficient, affixae; 
rami erecti ad 1 cm alt., saepius cicatrigene enascentes, 
saepius non ramosi, e segmentis 65-70-(100 ) li diam, 
et 0.7-1.5-(2.0) longioribus quam lata, membranas 
relative crassas ( 5.8p) habentibus, compositi; cellulae 
pericentrales 4, ecorticae; trichoblastae relative gros- 
sae, l-(3) dichotomias habentes, plerumque valde 
reductae et cito deciduae; cellulae-cicatrices in parti- 
bus superioribus, una in unoquoque segmento in I 
spira, plerumque, autem, intervallis 2-3 segmentorum 
infra et 1-3 segmentorum in ramis prostratis; cellulae 
pericentrales in ramis erectis vulgo paululum obliquae 
et non in ordinibus rectis longitudinalibus; tetra- 
sporangia in serie aliquantulum spirali usque in ad 30 
in serie, in partibus terminalibus ramorum erectorum; 
segmenta satis distendentia; plantae sexuales ignotae. 
type: D. 14696, on rocks in algal turf in a 
high tide pool near Koko Head Parking Area, 
eastern Oahu, legit E. Choy, Nov. 14, 1954. 
ADDITIONAL COLLECTIONS EXAMINED: HA- 
WAIIAN ISLANDS — D. 10667, north entrance 
shore of Hanauma Bay, Oahu, May 3, 1953; 
D. 22301.1, in tidepools, northeast bench of 
Hanauma Bay, Oahu, legit R. Tsuda, Jan. 17, 
1965 ; a collection by G. F. Papenfuss, Hanauma 
Bay, Oahu, Mar. 30, 1941 ; D. 19906A, Ilio 
Point, Molokai, Dec. 30, 1953; D. 22397, inter- 
tidal, in algal turf, Papawai Point, Maui, legit 
H., T., and B., Apr. 19, 1965 ; D. 22409-3 and 
D. 22410.4, in algal turf, 0.5 miles west of 
Papawai Point, Maui, legit H., T., and B., Apr. 
19, 1965; D. 13464.1, on a basalt ledge, west 
lip of Pohoiki Bay, Island of Hawaii, Nov. 
10, 1956; JOHNSTON ISLAND T. 1221, at a 
depth of 4 m, coral reef, northeast of East I., 
legit R. Buggeln, Aug. 20, 1965 ; society is- 
lands — a collection, D. 14698, by J. Randall, 
Tahiti, Mar. 12, 1956; American Samoa — T. 
359, on Caulerpa, reef flat near shore, Amanave 
Village, Tutuila, Sept. 4, 1963; Fiji islands — 
D. 12123.2, Navuevu Cuva, Singtoka, Viti 
Levu, Sept. 22, 1952; marshall islands — G. 
502, on H dime da in the lagoon at a depth of 
19 m, Eniwetok Atoll, Aug. 29, 1955; G. 781, 
on Halimeda at a depth of 53 m, in the lagoon, 
Eniwetok Atoll, Sept. 7, 1955; a collection, 
probably also by Gilmartin, tetrasporic, in algal 
turf at the outer edge of the reef, in front of 
the Marine Biology Laboratory, May 4, 1955; 
D. 9693C, on Halimeda sp., on the lagoon side 
of Ine Village, Arno Atoll, legit Leonard Hor- 
witz, Aug. 19, 1951; Caroline islands — D. 
15897.6, tetrasporic, on dead coral reef at Quoi 
I-, Truk Islands, legit E. Menez, July 30, I960; 
D. 21708.5, reef flat, Epwelkapw, Ponape L, 
legit E. Menez, Aug. 18, i960 ; D. 21740.1, 
on dead coral, reef on the eastern side of 
Mantapeitak I., legit E. Menez, June 20, I960; 
D. 23154.1, on dead coral, reef at Yap L, legit 
E. Menez, Aug. 19, I960; Philippine islands 
— D. 18213, on Acanthophora, Mawes, Hina- 
tuan, Surigao, legit E. Menez, July 7, 1958; D. 
18138, on rocks, reef flat at a depth of 3 ft, 
near Davao, Mindinao, legit E. Menez, June 22, 
1958; Indonesia — in the Rijksherbarium at 
Leiden, a collection by G. A. L. de Haan, No. 
30, Sumatra, Aug. 24, 1957 ; a Siboga Expedi- 
tion collection in the Rijksherbarium, from 
coral, Maumeri, Flores I. (8-9° S, 110-120 E), 
1880, along with Lophosiphonia cristata. The 
latter was identified by Weber-van Bosse as 
L. obscura (Ag.) Falk. 
Mention should be made of two collections 
by Dawson from Atlantic central America 
Da. 24356, south of Portete, Costa Rica, Aug. 
4, 1962; Da. 21910, Golfe de Fonseca, El Sal- 
vador, Aug. 7, I960. 
A variant form is represented by G. 502, 
abundant on Halimeda sp. at a depth of about 
19 m in the lagoon at Eniwetok Atoll, Marshall 
Islands, collected Aug. 29, 1955. It differs in 
the following respects: (1) scar-cells occur one 
per segment throughout; (2) the pericentral 
cells are hardly oblique; (3) the rhizoids arise 
£ the length of the pericentral cell from its 
distal end; (4) the tips of the rhizoids are 
discoid, with a lobed apex to which the separate 
marginal cells are attached ; ( 5 ) trichoblasts are 
unbranched or with a single branch and with a 
very long basal cell (to 240p long) ; (6) the 
erect branches tend to arise in pairs with 4 
segments between corresponding members of 
successive pairs. G. 781 is similar to the preced- 
ing in a number of the variant features. It was 
likewise growing on a Halimeda sp. at a depth 
of 5.3 m in the lagoon, Eniwetok Atoll. It 
was collected Sept. 7, 1955- D. 13464.1 like- 
wise represents this variant form in most re- 
spects. It was collected from a basalt ledge on 
