261 159 
Holm: Recherches anatomiques et morphologiques sur deux mono- 
cotylédones submergées (Halophila Baillonii Aschs. et Elodea densa 
Casp.); Bih. till k. Svenska Vet.-Akad. Handl. Bd.9, No. 13, 1885). 
Halophila decipiens Ostf.; nat. size. 
The Expedition has brought home a large material of this new Halo- 
phila, as well flowering as fruitbearing specimens preserved in alcohol. 
It resembles very much the Westindian H. Baillonis. 1 have examined 
for comparison a very large alcohol material of the latter (amongst other 
the same specimens as Mr. Theo. Holm has used for his above men- 
tioned carefull treatise), and I have found but a slight difference between 
this and the new species; the main difference consists in the absence of 
the short hairs on the ventral surfaces of the leaves in the new species, 
while H. Baillonis has short hairs on both sides. If the geographical 
distribution was not so quite different, I. should prefer to regard it as a 
variety of H. Baillonis, but it is not probable to suppose such a connection 
as. the sea-phanerogams generally have very natural and limited areas and 
H. Baillonis is confined to the shores of the Westindian Archipelago. 
From H. ovalis which is common along the shores of the Indian 
Ocean, the new species is very different; the moneecious flowers, the small 
teeth in the margins and the short hairs on the surfaces of the leaves, 
the few lateral veins etc. remove it far from this. 
Off Koh Kahdat, in 5 fathoms water (coral-sand). 
Lemnacez. 
Lemna L. 
4. I, paucicostata Hegelm., Die Lemnaceen, 1868, p. 139; Hook. f,, 
Fl. of British India VI, p. 556. 
Only sterile specimens have been collected. 
Koh Kong, in a poo). 
Avea: Tropical Africa, Asia, Australia and Polynesia; (tropical America®). 
