524 NEW AND RARE FRESHWATER ALG^t. 



thick, slightly coloured. Green cell remarkably small, retracted 

 to the apex: no stigma, no pyrenoid. 



Forma. (PI. Ivi., f.ll). 



Celluhe fronte A'is?e liaiid circiilatse sed modice quadratae, 

 iibique rotundatse; ad apicem qiiam levissime concavpe, papilla 

 nulla; ceteris ut in forma typica. 



Long. 21, lat. 19, crass. 14:; corp. 13/^. Lismore (312). 



Rather rounded-quadrate than circular in face-view, apex very 

 slightly concave, no papilla; other details as in the type. 



Forma. (PI. Ivi., f.l2). 



Cellulye ad apicem paullo quadratai, pone circulat?e; membrana 

 crassa, saturate rufescente; cytoplasmate in massa ovata retracto; 

 chloroplastide parietal! intus granulis amylaceis magnis ornata; 

 vacuolis contractilibus distinctis 2; stigmate mediano. 



Long. 21, lat. 20; corp. long. 12, lat. 10//. Lismore (345). 



In shape, intermediate between the two forms (sicpra), being 

 broad and "shouldered" above, and circular below. Membrane 

 deeply rufescent: cytoplasm retracted into a small ovate mass; 

 chloroplast parietal, granulate on the inner surface with large 

 granules; stigma distinct, median; two contractile vacuoles dis- 

 tinctly visible. These details are very rarely observable in 

 PhacotnK. 



Phacotus australis, n.sp. (PI. Ivi., f. 13, 14). 



Cellulie fronte vis;e fere circulatfe, ad apicem concaxie, papilla 

 insti-uctte; a latere valde compressse, ellipticse, apicibus acute- 

 I'otundatis. Membrana tenuis, glabra, dilutissime rufescens. 

 Cvtoplasma in massa apicali retractum, a latere visum com- 

 pressum, ovatum; stigmate nullo nee p^'renoidi. 



Long. 20, lat. 21, crass, c. 8//. Lismore (350). 



Almost circular in face-view with a slight apical concavity and 

 papilla ; from the side very compressed, elliptic with acutely 

 rounded ends. Membrane thin, smooth, pale biscuit-colour, with 

 a matt surface. Cytoplasm retracted, compressed, ovate, in side- 

 view: no stigma nor pyrenoid. 



