Marine Plants of Nha Trang — Dawson 
ably of the genus Gracilaria, for each has 
cystocarpic examples showing the distinctive 
nutritive filaments running from gonimoblast 
to pericarp. In 11424, antheridial examples 
are present among cystocarpic individuals and 
exhibit the conceptacular cavities character- 
istic of this species. However, it was discon- 
certing at first to find that intermixed among 
specimens under 11216 were some cystocarpic 
plants which proved to be of the genus Graci- 
lariopsis when sectioned (see below). These 
lack the nutritive filaments and have a goni- 
moblast of small cells with the sporangia in 
chains as shown by Dawson (1949, pi. 15, 
fig. 10) for Gracilariopsis . Superficially they 
could not be distinguished from specimens of 
Gracilaria verrucosa. Under 11090 other Graci- 
lariopsis specimens were recognized by their 
cystocarps, but in that collection no Gracilaria 
specimens were found, nor was antheridial 
material present. 
It is clear that in Cua Be, as in some local- 
ities in Mexico, species of Gracilariopsis and 
Gracilaria may intermingle in the same habitat 
and be quite indistinguishable macroscopic- 
ally. 
Gracilaria sp. 
Fig. 48<a^ 
The present material collected by Mr. Ser- 
ene at Cii Lao, May 4, 1950, is sterile and 
seems to be young. The most striking features 
of the plant are the contorted, dichotomous 
segments which are here and there attached 
to each other by accessory discs. In some 
respects the plant seems to approach Graci- 
laria corticata], Ag. or G. lingula], Ag., but 
is surely neither of these and is probably 
undescribed. Better developed and fertile ma- 
terial is needed. 
Gracilariopsis rhodotricha Dawson, prox. 
Dawson 1949: 47, pi. 19, figs. 3-7 (Revil- 
lagigedo Archipelago, Mexico) 
see Fig. 49 for habit 
LOCAL DISTRIBUTION: In drift, Sta. 3 
Fig. 49. Gracilaria verrucosa: Habit, X 1. 
(11090); growing with Gracilaria verrucosa^ 
Sta. 4 (11216a). 
Inasmuch as no antheridial material was 
found which could positively be identified 
with the cystocarpic examples, this determin- 
ation must remain open to question. It will 
be necessary to secure antheridial and cysto- 
carpic material from colonies apart from those 
