branched colonies. Most forms with silicaceous scales are now considered a separate group, the synurids, but a few belong among the Chromulinales proper, such as Paraphysomonas. Some members are generally amoeboid, with long branching cell extensions, though they pass through flagellate stages as well. Chrysamoeba and Rhizochrysis are typical of these. There is also one species, Myxochrysis paradoxa, which has a complex life cycle involving a multinucleate plasmodial stage, similar to those found in slime molds. These were originally treated as the order Chrysamoebales. The superficially similar Rhizochromulina was once included here, but is now given its own order based on differences in the structure of the flagellate stage. Other members are non-motile. Cells may be naked and embedded in mucilage, such as Chrysosaccus, or coccoid and surrounded by a cell wall, as in Chrysosphaera. A few are filamentous or even parenchymatous in organization, such as Phaeoplaca. These were included in various older orders, most of the members of which are now included in separate groups. Hydrurus and its allies, freshwater genera which form branched gelatinous filaments, are often placed in the separate order Hydrurales, but may belong here. Classifications Pascher (1914) Classification of the class Chrysophyceae according to Pascher (1914): Division Chrysophyta Class Chrysophyceae Order Chrysomonadales Order Chrysocapsales Order Chrysosphaerales Order Chrysotrichales Class Heterokontae Class Diatomeae Smith (1938) According to Smith (1938): Class Chrysophyceae Order Chrysomonadales Suborder Cromulinae (e.g., Mallomonas) Suborder Isochrysidineae (e.g., Synura) Suborder Ochromonadineae (e.g., Dinobryon) Order Rhizochrysidales (e.g., Chrysamoeba) Order Chrysocapsales (e.g., Hydrurus) Order Chrysotrichales (e.g., Phaeothamnion) Order Chrysosphaerales (e.g., Epichrysis) Bourrely (1957) According to Bourrely (1957): Class Chrysophyceae Order Phaeoplacales Order Stichogloeales Order Phaeothamniales Order Chrysapionales Order Thallochrysidales Order Chrysosphaerales Order Chrysosaccales Order Rhizochrysidales Order Ochromonadales Order Isochrysidales Order Silicoflagellales Order Craspedomonadales Order Chromulinales Starmach (1985) According to Starmach (1985): Class Chrysophyceae Subclass Heterochrysophycidae Order Chromulinales Order Ochromonadales Subclass Acontochrysophycidae Order Chrysarachniales Order Stylococcales Order Chrysosaccales Order Phaeoplacales Subclass Craspedomonadophycidae Order Monosigales Kristiansen (1986) Classification of the class Chrysophyceae and splinter groups according to Kristiansen (1986): Class Chrysophyceae Order Ochromonadales Order Mallomonadales Order Chrysamoebales Order Chrysocapsales Order Hydrurales Order Chrysosphaerales Order Phaeothamniales Order Sarcinochrysidales Class Pedinellophyceae Order Pedinellales Class Dictyochophyceae Order Dictyochales Margulis et al. (1990) Classification of the phylum Chrysophyta according to Margulis et al. (1990): Phylum Chrysophyta Class Chrysophyceae Class Pedinellophyceae Class Dictyochophyceae (= Silicoflagellata) van den Hoek et al. (1995) According to van den Hoek, Mann and Jahns (1995): Class Chrysophyceae Order