April, 1909.] The Classification of Plants, V. 491 



In the Mycophyta 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, Ptenophyta 

 (ptenos, feathered) is used, for the reason that " Pteridophy ta " 

 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 Strobilophyta, 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 phvla 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. 



Cvanophyceae. 



Schizomycetae. 



My xoschizomy cetae . 



2. Myxophyta. Slime Moulds. 400 species. 



Nonsexual unicellular plants without chlorophyll, having a 

 Plasmodium of more or less completely fused amoeboid cells and 

 usually building up complex sporangium-like resting bodies. 



My xomy cetae. 



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 



