A Synopsis of Plant Phyla g 



large, parietal, with one pyrenoid ; propagation by biciliated zoo- 

 spores; generation by heterogamctes, and the production of a 

 fruit. 



Family 17. Coleochaetaceae, with the characters of the order. 

 Minute freshwater plants. Cclcochaetc. (Pf. I, 2, iii.) 



Phylum III. ZYGOPHYCEAE. The Conjugate Algae. 



Plants microscopic, consisting t}'pically of simple unbranched 

 rows of cells, often separating early into isolated cells ; green, 

 with lamelliform, taeniform (ribbon-like), or granular chromato- 

 phores (in one class yellowish by the addition of phycoxanthin) ; 

 propagation by cell-fission ; generation by the union of the proto- 

 plasm of pairs of cells ("conjugation," or aplanatic isogamy). 



Class 5. CONJUGATAE. Chlorophyll-green plants with un- 

 silicified cell walls. Typically freshwater plants. 



Order Zygnemales. Plants filamentous, unbranched and cylin- 

 drical. Pond scums, floating in quiet fresh waters. 



Family i. Spirogyraceae. Chromatophores one to nine, taeni- 

 form, ■parietal, spiral. Spirogyra, Sirogoninvi. (Pf. I, 2, 16.) 



Family 2. Zygnemataceae. Chromatophores two, rounded or 

 stellate, axial. Zygncma, Zygogoniiini. (Pf. I, 2, 16.) 



Family 3. Mesocarpaceae. Chromatophore a single long axial 

 plate. Mougcotia, Gonatoncma. (Pf. I, 2, 21.) 



Order Desmidiales. Plants typically filamentous, but usually 

 separating early into single cells, mostly flattened. Desmids, 

 mostly in fresh water. 



Family 4. Desmidiaceae. Cells in unbranched filaments. Ge- 

 nicularia, Hyalothcca, Dcsmidium. (Pf. I, 2, i.) 



Family 5. Closteriaceae. Cells solitary, elongated, not at all 

 or but moderately constricted. Peniwn, Closterinm. (Pf. I, 2, 



I.) 



Family 6. Cosmariaceae. Cells solitary, broad, deeply con- 

 stricted. Cosniariuni, Micrastcrias. (Pf. I, 2, i.) 



Class 6. BACILLARIOIDEAE. Brownish-green plants con- 

 taining phycoxanthin in addition to chlorophyll; walls usually 

 silicified. Typically marine plants. 



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