Spongocladia vs. Cladophoropsis — PAPENFUSS 
accommodate two species, one of which was 
subsequently removed to Cladophoropsis by 
Bprgesen (1905). 
In 1888 Murray and Boodle published an 
account of the genus Spongocladia based 
upon a study of material of S. vauch eriae- 
formis from Mauritius and New Guinea and 
of two additional species from the south Pa- 
cific. They pointed out for the first time that 
the genus Spongodendron of Zanardini 
(1878), which was based upon two species 
(S. crassum Zanard. and S. dichotomum Za - 
nard. ) from New Guinea, was indistinguish- 
able from Spongocladia. Spongodendron 
crassum was found to be identical with Spon- 
gocladia vauch eriaeformis whereas Spongo- 
dendron dichotomum could be maintained as 
a distinct species under the binomial Spongo- 
cladia dichotoma (Zanard.) Murray et Boodle. 
In addition, Murray and Boodle gave a brief 
account and the formal diagnosis of a new 
species from New Caledonia, Spongocladia 
neocaledonica Grunow, which differed from 
the others in having a compact thallus. 
Up to the present no additional species of 
Spongocladia appear to have been described, 
but our knowledge of the genus has been en- 
larged in certain respects and the known geo- 
graphical range of two of the species has been 
extended. 
Heydrich (1894) reported S. vauch eriae- 
formis and S. dichotoma from the Ryukyu 
Islands, south of Japan. He was the first to 
bring attention to the fact that the thalli were 
not composed of a single plant but of a large 
number of individual Cladophora- like plants. 
In agreement with the observations of Zanar- 
dini and Murray and Boodle, he found that 
the filaments composing the thallus produced 
attachment organs, or tenaculae, by means of 
wdiich they anastomosed with near-by fila- 
ments, forming a kind of network. 
Heydrich was also the first to give an ac- 
count of the method of formation of the so- 
called aplanospores (or coniocysts, as they 
had been called by Zanardini ) , He regarded 
209 
Spongocladia as essentially a unicellular alga, 
which, like Valonia, formed aplanospores 
which produced daughter individuals that re- 
mained attached to the mother-plant. As we 
now know, the aplanospores of Heydrich 
were protoplasmic masses formed in conse- 
quence of segregative division, a characteris- 
tic feature of the order Siphonocladales. Like 
Hauck, Heydrich placed Spongocladia near 
Siphonocladus. 
In 1913 Weber- van Bosse recorded S. vau- 
cheriaeformis from Makassar and neighbor- 
ing islands in the Dutch East Indies. She ex- 
pressed the opinion that Spongocladia prob- 
ably represented special forms of algae known 
otherwise by different names. 
Okamura in 1916 recorded the occurrence 
of S. vauch eriaeformis at Ponape and Saipan 
in the Caroline and Marianas Islands, respec- 
tively. In a later work ( 1928), he confirmed 
the observation of Areschoug regarding the 
germination of spores (?) within the cells 
in which they were formed. He also saw and 
figured stages in their germination on the 
outside of filaments of the thallus. The ger- 
mination of spores (?) within the reproduc- 
tive structures was later observed by Yamada 
(1934) also. He appears to have been the 
first to have noted pores in the walls of the 
fertile cells, which suggests that the spores ( ? ) 
are motile and that those which had been 
seen within the cells had merely failed to 
escape, as is so often true in the algae. 
Although Okamura (1928) does not seem 
to have been fully aware of it, he clearly ob- 
served (see pi. 250, fig. 11) septation of the 
filaments by segregative division, thus con- 
firming the observation (in the light of pres- 
ent knowledge) of Heydrich. 
As far as I am aware, Dickie (1875), Jadin 
(1934), Lucas (1935), and Bprgesen (1940, 
1946, as well as 1948) are the only authors 
in addition to those already mentioned who 
have studied Spongocladia. Dickie, Jadin, 
and Bprgesen included S. vauch eriaeformis in 
their lists of algae from Mauritius, whence 
