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Trickodiscus elegans , Gen, et Sp. Nov, 
two divisions as non-motile cells. Aplanospores are also formed by the 
rounding off of the contents of the cells of the disc and branches ; when 
present they occur in large groups. 
Systematic Position. This plant does not appear to belong to 
any known genus of Chaetophoraceae, though it shows close affinity, 
in some respects, with Ckaetonema, Endoc Ionium , and Pseudochaete . Like 
these it is apparently one of those many reduced epiphytic forms (Huber, 2) 
which are closely allied to Stigeoclonium , and of which they have sometimes 
been considered as species. As regards their epiphytic nature, a few plants 
only were found growing on Azolla ; the others were on glass, a habitat on 
which epiphytes very easily develop (Cotton, 1). The relatively large disc 
and short upright branches are other epiphytic characteristics. 
DIAGNOSIS. The name Trickodiscus elegans is proposed for the plant, 
and a diagnosis is appended. 
Trickodiscus, gen. nov. 
Thallus parvus, epiphyticus, matrici arete adpressus, discum pseudo- 
parenchymaticum e filamentis radiantibus ramosis inter sese coalitis, ad 
marginem autem liberis, constitutum efformans, ramis erectis brevibus 
numerosis et pilis longissimis septatis ornatus ; cellulae uninucleatae chro- 
matophoro singulo parietal i lobato et pyrenoideo singulo praeditae. Re- 
productio per zoosporas, per isogametes biciliatas, per aplanosporas, et per 
cellularum palmelloidearum massulas. 
T. elegans , sp. nov. 
Characteres ut supra. 
Hah . ad plantas aquaticas {Azolla) ad Salem in Carolina septentrionali. 1 
Trickodiscus, gen. nov. 
Thallus small, epiphytic, closely adpressed to the substratum, and 
consisting of radiating branched filaments united to form a pseudo-paren- 
chymatous disc with free filaments at the periphery. It bears numerous 
short erect branches and very long septate hairs. Cells with parietal lobed 
chloroplast, one nucleus, and one pyrenoid. Reproduction by zoospores, 
biciliate isogametes, aplanospores, and palmelloid groups. 
T . elegans , sp. nov. 
Characters of the genus. 
Habitat . On Azolla collected at Salem, North Carolina. 
Discussion. Many Algae such as Stigeoclonium and Ulothrix have 
several methods of reproduction, and the occurrence of these has usually 
been correlated with changes in the environment. Klebs (3) described the 
variations which are produced by cultivating algae under different con- 
ditions. For instance, he records the fact that if plants of Stigeoclonium 
are grown on an artificial food solution the zoospores are not set free, but 
1 My thanks are due to Mr. A. Gepp for help in drawing up the diagnosis. 
R 
