150 Chlorophycex 



Group 2. Tetrasporineae. 



Families : Tetrasporacese ; Gloeocystacese ; Selenastracese ; Phy theliaceae ; 



Pleurococcaceae. 

 Group 3. Chlorococcineae. 



Families : Chlorococcacese ; Endosphaeraceae ; Hydrodictyacese. 



Series 2. Siphonales. 

 Group 1. Siphoneae. 



Families : Protosiphonacese ; Bryopsidaceae ; Derbesiaceae ; Caulerpaceae ; 



Codiaceae ; Verticillatae. 

 Group 2. Siphonocladeae. 



Families : Valoniacese ; Gomontiaceae ; Cladophoraceae ; Sphseropleacese. 

 Series 3. Ul vales. 



Family : Ulvacese. 

 Series 4. Ulotrichales. 



Families : Ulotrichaceae ; Prasiolacese ; Microsporacese ; Cylindrocap- 

 sacesB ; Chsetophoraceae ; Chaetosiphonaceee ; Coleocheetaceae ; Chroo- 

 lepidaceae. 

 Class II. Stephanokontx. 



Family : (Edogoniaceae. 

 Class III. Conjugate (Akontse). 

 Series 1. Desmidioideae. 



Families : Archidesmidiaceae ; Eudesmidiaceae. 

 Series 2. Zygnemoideae. 



Families : Spirogyraceae ; Zygnemacese ; Mougeotiaceaa. 



Class IV. Heterokontx. 



Series 1. Chloromonadales. 



Families : Chloramoebacese ; Vacuolariacese ; Chlorosaccaceee. 

 Series 2. Confervales. 



Families : Chlorotheciacese ; Confervaceaa ; Botrydiacese. 

 Series 3. Vaucheriales., 



Families : Vaueheriacese ; Phyllosiphonaceae. 



II. In the Treatise on the British Freshwater Algae (G. S. WEST, '04) the classifica- 

 tion put forward was not essentially different from that suggested by Bohlin, except that 

 the genus Prasiola was placed in a separate group, the Schizogoniales. It would have 

 been better, however, if the Heterokontse had not been given such undue prominence, and 

 the Conjugated removed from the middle of those Algse which are now regarded as 

 constituting the Isokontse. The detailed treatment of the Conjugates was entirely different 

 from that followed by Blackman & Tansley, and the Vaucheriaceee were retained in the 

 Siphoneae. Bohlin was followed in regarding the genus Microspora as the sole representa- 

 tive of the group * Microsporales.' 



III. OLTMANNS ('04) put forward a classification of Green Algae in many ways 

 peculiar. His inclusion of the diatoms within the Akontse is not only extraordinary, but 

 constitutes an extension of the group ' Akontae ' which can hardly be countenanced and is 

 most decidedly confusing. Similarly, his division of the Conjugatae into the Mesotaeniaceae, 

 Zygnemacese and Desmidiacese, with the inclusion of Oenicularia and Gonatozygon in the 

 Zygnemaceae, is not altogether in accordance with the present-day knowledge of this group. 



