Up to the present time about 39,000 species have been described.
Review of the divisions of the Fungi:—
Class I.—Phycomycetes (Algal-Fungi).
- Sub-Class 1. Zygomycetes.
- Sub-Class 2. Oomycetes.
- Family 1. Entomophthorales.
- Family 2. Chytridiales.
- Family 3. Mycosiphonales.
Class II. Mesomycetes.
- Sub-Class 1. Hemiasci.
- Sub-Class 2. Hemibasidii (Brand-Fungi).
Class III.—Mycomycetes (Higher Fungi).
- Sub-Class 1. Ascomycetes.
- Series 1. Exoasci.
- Series 2. Carpoasci.
- Family 1. Gymnoascales. }
- Family 2. Perisporiales. }Angiocarpic Exoasci.
- Family 3. Pyrenomycetes. }
- Family 4. Hysteriales. }
- Family 5. Discomycetes. } Hemiangiocarpic Exoasci.
- Family 6. Helvellales. Gymnocarpic (?) Exoasci.
- Additional: Ascolichenes. Lichen-forming Ascomycetes.
- Sub-Class 2. Basidiomycetes.
- Series 1.—Protobasidiomycetes. Partly gymnocarpic, partly angiocarpic.
- Series 2. Autobasidiomycetes.
- Family 1. Dacryomycetes. Gymnocarpic.
- Family 2. Hymenomycetes. Partly gymnocarpic, partly hemiangiocarpic.
- Family 3. Phalloideæ. Hemiangiocarpic.
- Family 4. Gasteromycetes. Angiocarpic.
- Additional: Basidiolichenes. Lichen-forming Basidiomycetes.
- Additional to the Fungi: Fungi Imperfecti. Incompletely known (Saccharomyces, Oidium-forms, etc.).
Class 1. Phycomycetes (Algal-Fungi).[12]
This group resembles Vaucheria and the other Siphoneæ among the Algæ.