60 
PACIFIC SCIENCE, Voi. XV, January 1961 
1930), and from all other species known to 
the authors, in the reproductory structures 
described for these taxa and on the basis of their 
being more branched and larger in size. Speci- 
mens of H. calvadosii from France (University 
of California Herbarium no. 407401, identified 
by Kylin) measured 26-36 cm. tall, and in the 
parts examined lacked any trace of the sterile 
rhizoid-like filaments characteristic of our 
species and of H. papenfussii. Another specimen 
(University of California Herbarium no. 
218320, labeled by Rosenvinge H. purpurea) 
was up to 60 cm. tall and likewise lacked the 
peculiar rhizoidal filaments around the hypo- 
gynous cells. This latter specimen was the most 
nearly simple in branching of any Helmin- 
th ocladia examined by us aside from H. simplex . 
In regard to the enveloping rhizoidal filaments 
our organism is unlike H. calvadosii (Kylin, 
1930), H. hudsoni (Feldmann, 1939) which 
have no such filaments, and H. papenfussii as 
described by Martin (1939) which has many 
such filaments. The most striking of these 
sterile filaments (Figs. 8, 9, 12, 14) arise from 
the cell above the supporting cell in the vegeta- 
tive branch, but they are more complex than 
those Balakrishnan (1955) illustrates for Lia- 
gora erecta. 
Martin (1939) ascribes both a fusion cell to 
Helminth ocladia papenfussii, derived from the 
carpogonial branch, and a sterile envelope; these 
are illustrated in her figures 20 and 21. By the 
time a gonimoblast is this far developed in this 
Hawaiian species, there is no indication of either 
such a fusion cell or such an enveloping basket 
of sterile branches. The sterile rhizoidal branches 
develop in H. simplex as in some other Hel- 
minth ocladia species where such may be found, 
primarily from the cell above the supporting 
cell in the vegetative branch, as Kylin ( 1938, 
fig. 1C) illustrates H. papenfussii. The first to 
appear tend strongly to encircle the young 
gonimoblast but they were not seen in older 
stages. Desikachary (1956, figs. 25, 29) illus- 
trates a similar situation in Helminthora lind- 
aueri from New Zealand. 
The material reported and figured as Hel- 
minth ocladia australis by Okamura (1916: 21) 
and by Segawa (1957: 58, fig. 254) seems to 
be similar to ours in habit, except for the larger 
size and greater degree of branching. However, 
Narita’s ( 1918) figure of H. yendoana, which 
in that author’s opinion includes H. australis 
of Okamura, does not resemble our alga at all. 
Furthermore, our examination of certain speci- 
mens (University of California Herbarium nos. 
335335, a female thallus apparently identified 
by S. Narita; 279932, a female thallus identified 
by Y. Yamada; and 418162 ) shows the Japanese 
material to be different in other details as well. 
From the materials illustrated and discussed as 
H. australis by Desikachary (1957&), our mate- 
rial differs in being far simpler and smaller. 
We refer here only briefly to the rhizoids 
(Fig. 18 r) which develop from the lower cells 
of the cortical filament systems. Only rarely 
was there any indication of such a rhizoidal 
filament (see r in Figs. 2) in the outer part 
of the cortex that even recalls slightly the 
rhizoids peculiar to the next species. Figure 
18 f i -?*4 perhaps illustrates the ontogeny of this 
rhizoidal type. Note that the cortical cells (Fig. 
18) are, in general, characteristic for Helmin- 
th ocladia. 
Helminth ocladia rhizoidea sp. nov. 
Figs. 19-24 
DESCRIPTO TYPI: Thallus 9 cm. alt., valde 
mucosoideus, in partibus inferioribus radiatim 
ramosus; filamenta corticea usque ad 350 /x long., 
irregulariter dichotome tritomeve ramosa; cel- 
lulae apicales amplificatae, pyriformes, 13-26.5 
fx lat., 45 fx long.; rhizoidea multa 4.8-7.2 g 
lat., e filamentis corticeis exterioribus producta; 
gonimoblastus involucro filamentorum e cel- 
lulis minoribus quam cellulae corticis vegeta- 
tivi consistantium, aliter, autem, filamentis as- 
similativis corticeis propinquis similium, cir- 
cumdatus; filamenta involucri e cellulis vege- 
tativis infra superque cellulam sustinentem pro- 
ducta. 
The holotype is a preparation bearing the 
collection number MDoty 12860. The specimen 
was collected by Mr. Tetsuo Matsui at Lahaina 
(156° 41' W., 20° 53' N.), on the island of 
Maui, Hawaii, and it is deposited in the Bernice 
P. Bishop Museum, Honolulu, Hawaii. 
