132 JOHN H. SCHAFFNER Vol. XXII, No. 5 



Phylum, GoNiDioPHYTA. Zoospore Plants. 



SYNOPSIS OF THE CLASSES OF GONIDIOPHYTA. 



I. Plants unicellular or colonial, not truly filamentous. 



A. Nonsexual, unicellular or colonial algae without zoospores, commonly 

 with autospores; cells normally with one nucleus. Autospor^. 



B. Isogamous or heterogamous, sexual algas or probable derivatives from 

 them, with zoospores. 



1. Unicellular or colonial algae, usually with one nucleus in each cell, 

 rarely cenocytic; the colonial forms not produced by the sym- 

 metrical aggregation of free zoospores into a definite colony; 

 vegetative stage nonmotile or active. Isogamus or heterogamous. 

 Chlorococce^e. 



2. Cenocytic algae consisting of colonies of peculiar form, new colonies 

 being produced by the definite arrangement of daughter cells 

 developed in the parent cenocyte; isogamous, aquatic. 



Hydrodictye^. 

 II. Green algas with a filamentous or massive body and with 1, 2, 4, or many 

 cilia on the zoospores and gametes. 



A. Cenocytic, septate or nonseptate, isogamous or heterogamous. 



1. Vegetative body usually septate, consisting of a series of cenocytes; 

 chloroplasts forming a net, rarely in separate plates. Siphonoclade^. 



2. Vegetative body usually nonseptate, with distinct lenticular, oval or 

 plate-like chloroplasts. Siphone.^. 



B. Algas having normal cells with one nucleus, with a conjugation of free 

 swimming gametes or with motile sperms and stationary eggs. CoNFERVEiE. 



Class, Autospor^. 200 species. 



I. Reproduction by autospores, the protoplast dividing within the mother cell, 

 and the daughter cells escaping singly or in colonies. In fresh, brackish, or 

 sea water, or on moist rocks, etc.; some endozoic in water animals. Sele- 

 nastrales. vSelenastracege, Oocystaceae, Chlorellaceas, Tetraedraceae, Scene- 

 desmaceae, Sorastraceae. 

 II. Reproduction by vegetative division and separation by splitting of the 

 daughter cells. (Doubtfully placed in the Autosporas). Aerial, on damp 

 stones, trees, etc., or in fresh or salt water. Protococcales. Protococcaceas. 



Class, Chlorococce/E. 250 species. 



I. Cells ciliated and motile in the vegetative state; unicellular or in definite 

 colonies. Volvocales. Chlamydomonadaceae, Volvocaceae. 

 II. Cells not active in the vegetative stage. 



A. Vegetative cell divisions absent, cells separate or somewhat cenocytic. 

 Chlorococcales. Chlorococcaceae, Chloretheciaceae, Ophiocytiaceae. 



B. Colonies increasing by vegetative cell division. Tetrasporales. 

 Botryococcaceae, Tetrasporaces. 



Class, Hydrodictye.e. 30 species. 

 One order, Hydrodictyales. Pediastraceas, Hydrodictyaceas. 



Class, S1PHONOCLADE.E. Lower Tube Algae. 450 species. 



I. Plants isogamous or slightly heterogamous; filaments branched. Clado- 

 phorales. Valoniaceas, Cladophoraceae, Siphonocladacese, Dasycladaceae. 

 II. Plants heterogamous^ with stationary eggs and motile spermatozoids; 

 filaments septate,.unblfmched, free-floating. Sphaeropleales. Sphaeropleaceae. 



