72 
PACIFIC SCIENCE, Vol. XXII, January 1968 
H alime da sp., in surge channel, south reef of 
McKean I., Oct 21, 1964; L. 2644.5*, on 
Halimeda sp., Birnie I., Nov. 8, 1964; L. 
2659.1, in algal turf on intertidal rocks, north- 
east reef of Enderbury I., Nov. 9, 1964; 
MARSHALL islands — H. 48-0914.20, outer reef 
of Uku L, Bikini Atoll, July 9, 1948; H. 
48- 2894.5, Nama I., Bikini Atoll, July 15, 
1948; H. 48-Y23, Japtan I., July 23, 1948; 
Caroline islands (all legit E. Menez, Aug., 
I960) — D. 23032.2*, on Mkrodictyon sp., on 
reef between Ifaluk and Falalap islands, Aug. 
10; D. 23056.1, on coral and other algae, on 
reef, northeast end of Puluwat I., Aug. 7; D. 
23167.1 and D. 23207.1, among smaller algae, 
southern tip of Sorol I., Aug. 13; D. 23674.1, 
with other algae, western end of Puluwat L, 
Aug. 7. 
A collection by A. J. Bernatowicz, 53-358, 
from Bailey’s Bay, Bermuda, May 14, 1953, 
agrees in most details with the description given 
for this species, although the prostrate branches 
are somewhat more extensive and rhizoids have 
multicellular tips. No fruiting was observed in 
the Bermuda specimens. 
A minute variant form of this species (Fig. 
3 B) is represented by H. 65-133 (Fig. 3 B), 
cystocarpic, collected by R. S. Jones north of 
North I., Johnston I., Apr. 22, 1965. It is 
only 500p high with erect branches to 75p in 
diameter, with very delicate trichoblasts and 
with immature cystocarps on both erect and 
prostrate branches. No additional collections 
of this variant are available. 
P. poko var. longii var. nov. 
Fig. 22 
With the general features of the species but 
relatively coarse, with erect branches to 1.3 
cm high and commonly with 1-3 unilateral 
branches, and with the tips of erect branches 
frequently functioning as stolons and forming 
new prostrate branches ; tetrasporangial branches 
to 3 mm long and 1 1 5 p in diameter toward the 
base, mostly unbranched, and with 20-30 spi- 
rally arranged tetrasporangia, which are only 
slightly protuberant, and in some cases with 
evidence of at least as many tetrasporangia 
having been previously released from the lower 
segments. 
Varietas proprietales speciei generales praebens, 
plantae, autem, relative grossae, ramis erectis ad 1.3 
cm alt., et vulgo 1-3 ramos unilaterales habentibus, 
necnon cacuminibus ramorum erectorum velut stoloni- 
bus saepe fungentibus et ramos prostrates novos for- 
mantibus; rami tetrasporangiales ad 3 mm long., et 
1 1 5 pL diam. ad basim, magna ex parte non ramosi, 
20-30 tetrasporangia spiraliter ordinata, vix protuber- 
antia ferentes, signa indicantia quod saltern totidem 
sporangia e segmentis inferioribus paulo ante liberata. 
type: L. 2709.1, tetrasporic, from exposed 
coral heads near breaking waves on the south- 
west reef of Jarvis I., Line Islands, Nov. 16, 
1964; glucose slide mounts and fluid preserved 
material. 
ADDITIONAL collections: Two are identi- 
fied with this species — L. 2703.1, tetrasporic, 
from exposed and protected parts of depres- 
sions and ridges on coral heads, near breaking 
waves, Jarvis L, Nov. 16, 1964; a collection by 
David Sigee No. 35 from Gan I., Addu Atoll, 
Maidive Islands in the Indian Ocean, July- 
Sept, 1964. One other collection is placed in 
this variety with some reservations, L. 2451.11, 
with matted algae, north shore of Gardiner I., 
Line Islands, Oct. 23, 1964. In this the seg- 
ments of prostrate branches are as long or 
longer than broad (lOOp in diameter) and 
have rhizoids with multicellular tips. 
Polysiphonia profunda sp. nov. 
Figs. 18, 20 
Minute, epiphytic algae with prostrate 
branches attached by unicellular rhizoids with 
digitate tips cut off from the proximal end of 
the pericentral cells or sometimes with a basal 
group of rhizoids and no prostrate branch; 4 
ecorticate pericentral cells slightly flattened tan- 
gentially, with segments mostly less than one 
but occasionally 1. 5-2.0 diameters long and 
with stratified walls to 15p thick and brownish 
in older parts ; erect branches apparently of 
cicatrigenous origin; 125-l45p in diameter and 
4-6 mm long, with few lateral branches ; lateral 
branches arising in connection with trichoblasts 
or cicatrigenously at intervals of 20-30 or more 
segments; trichoblasts very slender, to 400 
(500) p long and 8-1 2p in diameter at the 
base, with 3-4 forks, arising one per segment 
in J spiral sequence, relatively persistent but 
when shed leaving small scar-cells 7-8p in 
