^8 BIOLOGY OF THE RICHMOND RIVEk, 



Spirogyra Lismorensis mihi. (PI. iii , f.l). 



Diam. cell. veg. 14; cell. alt. 80-300 /x. 



Lismore(12). 



Cells very long for the diameter, containing a single broad 

 chloroplast, not wound spirally, but twisted round its long axis; 

 pyrenoids in a single row down the centre; chloroplast making 5 

 to 15 turns, edge somewhat laciniate; ends of the cells reflexed 

 2 /x. I have given this curious and interesting form a name, but 

 I do not consider it a distinct species. It is highly probable that 

 each chloroplast splits longitudinally into two which become 

 spirally disposed. Some were already divided at the ends, and 

 there were other Spirogyra filaments with two taeniae in the same 

 gathering. The latter (diam. 18/x, cell. alt. ca. 160//) might be 

 Sp. ivflata (Vauch.) Rab., but with both forms infertile, there 

 could be no certainty about either. Cf. Spir. Goetzei Schm., 

 Ergeb. d. Nyassasee, p.251, PI. iv., f.8. 



DESMIDIACE^. 

 Genus Gonatozygon DeBary. 

 GoNATOZYGON KiNAHANi (Arch.) Rab., f. (PI. iii., f.32). 

 Forma apicibus extremis quam levissime angustatis. 

 Long. 288-470, lat. 13-14, ap. 12-13 /x. 

 Lismore (18). 



The apices, which are generally somewhat inflated, are in this 

 form just a little narrower, no membranous tag at the angles. 



Genus Penium Breb. 

 Penium australe, forma crassior G. S. West. 



Zygospora matura globosa, levita angulata, spinis brevibus e 

 tumoribus orientibus ad angulos munita, spinis maturis bifidis. 

 Membrana crassa. 



Long. 66-90, lat. 48-54. Zygo. diam. s. sp 65; spin. long, ad 

 14 /x; membr. 4 /x. 



Lismore (12), Casino (14). 



Cf. G. S. West, Third Tanganyika Exp., p.l08, P1.6, f.4. The 

 diameter of the type is 38 /x. The endochrome is arranged in two 



