April, 1909.] 
The Classification of Plants, V. 
49 1 
In the Mvcophyta are included not only the higher fungi but 
also the Zygomycetae and Oomycetae. These two classes may 
have affinities with the Siphoneae in the Gonidiophyta but their 
exact relationships with these plants appear obscure at present 
and the gap is as great if not greater than that which separates 
them from the lower Ascomycetae. The Laboulbenieae may 
belong with the Rhodophyta. 
For Bessey’s “Pteridophyta” a new name, Ptenophvta 
(ptenos, feathered) is used, for the reason that “Pteridophyta” 
has become too well established as a term of much wider applica¬ 
tion in which sense it will still be needed when the phyletic 
scheme of classification is adopted. The Gneteae, which consist 
of three very distinct families, Tumboaceae, Ephedraceae, and 
Gnetaceae, are considered to be modified Strobilophvta, the same 
tendencies showing here as are to be discovered in several lines of 
the Anthophyta. The Ephedraceae are no doubt a distinct order, 
the other two families showing some relationships to each other. 
The phyla with their classes and approximate number of 
species, may be characterized as follows: 
1. Schizophyta. Fission Plants. 2,400 species. 
Nonsexual, unicellular or filamentous fission plants of simple 
structure, with or without chlorophyll but never with a pure 
chlorophyll-green color. 
Cyanophyceae. 
Schizomvcetae. 
Myxoschizomycetae. 
2. Myxophyta. Slime Moulds. 400 species. 
Nonsexual unicellular plants without chlorophvll, having a 
plasmodium of more or less completely fused amoeboid cells and 
usually building up complex sporangium-like resting bodies. 
Myxomycetae. 
3. Diatomeae. Diatoms. 3,000 species. 
Brownish-green unicellular or unbranched filamentous algae 
with diatomin and silicified cell walls consisting of two valves, 
and with or without a conjugation of the cells. 
Diatomeae. 
4. Conjugatae. 1,200 species. 
Unicellular, or unbranched, filamentous, green algae without 
silicified cell walls, with zygospores produced by the conjugation 
of the cells. 
Conjugatae. 
5. Gonidiophyta. 2,000 species. 
Unicellular, filamentous, or thalloid, sexual or nonsexual, 
plants, green in color or without chlorophyll, nearly all producing 
