480 _ ETHEL S. BARTON ON THE MARINE ALGE 
The position of this species has hitherto been regarded as 
obscure, since all that was known of it was the short description 
given by Dickie (‘On the Alge of Mauritius,” Journ. Linn. Soc., 
Bot. vol. xiv. 1875, p. 191). ‘* Ectocarpus spongiosus, n. sp.— 
Filis decomposito-ramosis, in funiculos obtusos densissime im- 
plexis ; ramulis brevibus, alternis, bifidis vel trifidis. Propagula? 
The joints are about as long as broad, those of the ramuli a half 
longer than broad. The plant is dark brown, very sponge-like 
in habit.” 
Specimens of the plant are included in the present collection 
from the Laccadive Islands, and it is now possible to add further 
details as to the structure and to figure the fruits. Portions of 
the original material collected by Pike at Mauritius are pre- 
served both in the British Museum and Kew Herbaria, and an 
examination of these specimens shows that plurilocular sporangia 
are present, but were overlooked by Dickie. They correspond 
closely with those of the material now obtained from the Lacca- 
dive Islands. They are terminal on a stalk of 1 cell, and are 
about 40-50 long and about 40» broad. They appear to 
be divided into 6 or 8 loculi; but as the sporangia of the Lacca- 
dive material are not quite mature, it has not been possible to 
figure one with all the walls of the loculi complete. In several 
instances a new sporangium has clearly grown up through the 
stalk-cell of an old one, as is seen by the collar of old tissue 
round the new stalk-cell. 
Both in Dickie’s description and the pencil sketch which accom- 
panies his type specimen of H. spongiosus in the British Museum, 
the branches are said to be bifid or trifid; but though there are 
traces of this in the material itself, it is neither a conspicuous 
nor a characteristic feature. The ends of the branches are very 
often curled right round on themselves, and this is also very 
marked in the Laccadive material. 
In the British Museum there is a ‘ Challenger’ specimen 
from the Admiralty Islands named by Dickie Eetocarpus sor- 
didus, Harv., but upon examination it proves to be a good 
example of E. spongiosus in fruit. A sterile plant of EZ. spongiosus 
is included among the alge collected by the ‘Investigator’ at 
Sail Rock, Cheduba Straits, off the Burmah coasts. 
