16 G 
THE JOURNAL OF BOTANY 
S. acuminatus (Lagerh.) Chod. Loc. 12, 38. Distr. Eur., 
Austral., Indo-Malaya. 
S. acutiformis Schroder. Loc. 9. Distr. General. 
S. quadricauda (Turp.) Breb. Loc. 13, 23, 29, 37, 38, 41, 44. 
Distr. General (incl. Ceylon). 
S. oahuensis (Lemm.) G. M. Smith Loc. 6, 9. Distr. Sand¬ 
wich Isles. 
S. opoliensis P. Kichter. Loc. 4, 12. Distr. Eur., Afr., 
N. Amer., Java, Ceylon. 
S. c arinat us (Lemm.) Chod. Loc. 13. Distr. Eur., Java. 
S. tropicus, n. sp. 
Ccenobio subquadrato perforato 4-cellulario, cellulis bieonvexis, 
maxima latitudine ad paene tertiam partem longitudinis, ad apices 
inflatis; cellulis terminalibus in spinas ad utrumque finem provectis ; 
spinis extrorsum recurvis, tarn longis quam cellulte corpus; cellulis 
inter se hserentibus compressis pulvillis ; foraminibus angustis lineari- 
bus inter cellulas. Chlorophoris singulis, singulis pyrenoidibus. 
Cellulis 31-33 p longis, raro minoribus. 
Sceneclesmus tropicus Crow, n. sp. 
This is one of the few perforate species, easily distinguished 
from S. perforates by its narrower cell connections, the biconvex 
form of the cell, the four-celled character and size of the colonies. 
Turner’s S. quadricauda var. major , also an Indo-Malayan form, is 
perhaps to be placed as a variety of this. Although imperfectly known, 
it is plainly not identical with S. tropicus (fig. 2). The intercellular 
pads are well-developed, although narrow, and result in very clearly 
perforate colonies. The pads, as in other species, are outgrowths of 
an outer mucilage layer of the cells ; in S. tropicus this is particu¬ 
larly well seen, it being clear that each connection is not a continuous 
bridge, but rather two adpressed pads one from each cell (fig. 2). 
Loc. 6. 
S. arcuatus Lemm. Loc. 4. Distr. Eur., Afr., N. and S. Amer. 
S. armatus (Chod.) G. M. Smith. Loc. 18. Distr. Eur., 
Samoa, Singapore. 
S. Bernardii G. M. Smith. Loc. 18. Distr. ~N. Amer. 
Actinastrum Lagerh. 
A. Hantzschii Lagerh. Loc. 6, 9, 50. Distr. Cosmopolitan. 
