Helminth ocladia — Doty and Abbott 
57 
Fig. 1. The type of Helminth ocladia simplex, a 
preparation on a herbarium sheet. 
plerumque tenuiores, clore nitidiores, altiores, 
magis ramosi. Thalli textura ubique lubrici mol- 
lesque. Frondes mnltiaxiales, filamentis corti- 
calibus nullo modo inter se adhaerentibus. 
The holotype is a preparation of six thalli on 
one herbarium sheet deposited in the Bernice 
P. Bishop Museum in Honolulu, Hawaii. These 
specimens, along with a small Liagora, formed 
a turf on an almost horizontal rock surface just 
above extreme low tide line. The type material 
was collected by Jan Newhouse and Henry Ke- 
koanui (M. Doty no. 12691) at Kahanahaiki, 
Waianae, Oahu, Hawaiian Islands (21° 32' N., 
158° 14' W.), Jan. 2, 1954. Isotypes are be- 
ing sent to the herbaria of the University of 
California, University of Michigan, Hopkins 
Marine Station of Stanford University, Cryp- 
togamic Laboratory of the Paris Museum, Uni- 
versity of Adelaide, South Australia, and Hok- 
kaido University at Sapporo, Japan. 
During some of the years since the original 
collection was made by Newhouse and Keko- 
anui, the type locality has been revisited. The 
sand shifts a great deal throughout the year 
at this site; sometimes the place is completely 
covered with sand. Until recently the alga had 
not been refound, though other members of 
the Helminthocladiaceae were often present in 
abundance. However, on Apr. 10, I960, while 
Doty was accompanied by Newhouse and Er- 
nani Menez, a dense stand of H. simplex (M. 
Doty no. 19135A, Menez no. 201) was found. 
The thalli were essentially of the same mor- 
phological form and were collected in the same 
place under the same conditions as the type. 
The living material was yellowish brown, with 
no taste or odor, and hard like a Gracilaria 
rather than soft like a Trichogloea. Perhaps a 
half liter of the species was obtained at this 
time. In time the algal population dwindled 
and the sand as well, until by May 8 there was 
very little of either on the site. The form of 
the Helminth ocladia simplex present at this 
time was still the same as the other collections 
of this species, or perhaps a bit more eroded. 
Thalli (Fig. 1) of irregularly cylindrical 
branches, up to 9.5 cm. tall, with most of the 
subsimple axes and branches 1-1.5 mm. in diam- 
eter. Branches irregular in arrangement and 
few. Thalli often simple, and these simple ones, 
while often of larger diameter than branched 
thalli, are rarely more than 2-4 mm. in diameter. 
Often the simpler thalli of more irregular form 
that are duller in color and shorter in stature 
are carpogonial. The antheridial thalli are gen- 
erally more slender, more brightly colored, taller, 
and more branched. Texture rubbery and pliant 
throughout. The fronds are multiaxial and the 
cortical filaments do not adhere to each other 
in any way. 
Our material is dioecious. No evidence of 
what might be a tetrasporangial generation was 
seen. 
The male thalli produce spermatangia on 
terminal cortical cells among the vegetative 
filaments of the surface. The spermatangia are 
produced on cells (Fig. 2s) that are smaller 
than the adjacent vegetative cells and terminate 
in dichotomous rows of small cells. These small 
masses of cells do spread out under the cover 
glass on a microscope slide as do the terminal 
fans described for Helminth ocladia by Martin 
(1939), but one suspects them of covering the 
surface area of the vegetative terminal cells 
they replace; i.e., occurring in round brushlike 
clusters rather than in two-dimensional fans. 
More than one spermatium may adhere to a 
trichogyne; those seen stuck to trichogynes were 
colorless. 
The female apparatus develops laterally from 
the fourth or fifth cell (Figs. 3, 4, 5) below 
the enlarged terminal superficial cortical cell. 
