Revisions of Some Plant Phyla 7 



Family 21. Derbesiaceae. Plants filamentous, sparingly dichot- 

 omous, erect, with basal rhizoids, zoospores multiciliated. Der- 

 besia. (Pf. I, 2, 129.) 



Family 22. Bryopsidaceae. Sea Ferns. Plants pinnately 

 branched, erect, with basal rhizoids ; gametes biciliated. Bryopsis. 

 (Pf. I, 2, 127.) 



Family 23. Caulerpaceae. Caulerpas. Plants large, branched, 

 creeping, with lateral rhizoids and bearing erect, usually pinnate 

 "leaves." Caulerpa. (Pf. I, 2, 134.) 



Family 24. Dasycladaceae. Sea Umbrellas. Plants erect, reg- 

 ularly branched in whorls, with basal rhizoids. Botryophora, 

 Acctabularia. (Pf. I, 2, 152.) 



Order Charales. The Stoneworts. Green plants consisting of 

 erect rooted, septate, dendroid stems, bearing whorled branches. 

 Stems and branches composed of large, long coenocytes which are 

 often covered (corticated) with smaller coenocytes. Antheridial 

 branches compounded into a globular structure containing many 

 sperm-bearing filaments, the true antherids ; sperms biciliated ; 

 oogone rounded, covered with a twisted layer of protective cells, 

 terminating in a 5 or 10 celled crown. 



Family 25. Nitellaceae. Crown of oogone composed of ten 

 cells. Nitella, Tolypella. (Pf. I, 2, 172.) 



Family 26. Characeae. Crown of oogone composed of five 

 cells. Chara, Tolypelopsis, Lamprothamnus, Lychnothamnus. 

 (Pf. I, 2, 174.) 



Phylum VI. RHODOPHYCEAE. The Red Algae. 



Plants aquatic, from filamentous to erect, well differentiated 

 stems, which are rooted below and sometimes bear flat, leaf-like 

 structures ; propagation by non-motile tetraspores, or by simple 

 fragmentation of the plant body; generation by heterogametes, 

 the fertilized tgg developing into one or more (often many) 

 spores, which are enclosed in a sterile tissue, the whole constitut- 

 ing a primitive fruit. In addition to chlorophyll the plants of 



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