354 FRESHWATER AT.O-^ OF LISMORE DISTRICT^ 



Genus Oscillatoria Vaucher. 

 OsciLLATORiA PRiNCEPS Vaucher (PI. xlvi., t'.lO.) 

 Trich. diam. 28-44, ap. 18; cell. alt. 4-8 /x. 

 Lismore(187). 



Gomont, I.e., p. 207, PI. vi., f.9. Colour pale grey-green, pro- 

 toplasm very finely granular, dissepiments not granulate. Speci- 

 mens are often found with a very thick sheath, and there are 

 indications of permanent septa across the sheath between the 

 cells (PI. xlvi., f.lOc). Found only in the river here. 



OsciLLATORiA CORAKIANA, n.Sp. (PI. xlvi., f.ll.) 



Fila lata, vaginis observatis. Trichomata subrubicunda vel 

 atrochalybea, viridi tincta, interdum ad genicula constricta; 

 apicibus leviter attenuatis rotundatis, aut arcuatis subtruncatis; 

 cellulis angustis ; dissepimentis conspicuis, gianulatis; proto- 

 plasmate minute granulato. 



Trich. diam. 11-12; cell. alt. 2-4 /x. 



Coraki (202). 



The colour of the trichomes, a pale pinky-brown, or dark grey, 

 flashed with pale green, seems to distinguish this species from 

 all others. The trichomes are sometimes constricted, sometimes 

 not; it is a character that I find to be of very doubtful value. ( 



OsciLLATORiA FORMOSA Bory. (PI. xlvi., f.l2, 13.) 



Trichomata dilute cyanea vel dilute viridia, vulgo ad genicula 

 constricta sed non semper, dissepimentis rarissime granulatis. 



Trich. diam. 4-7; cell, alt 2-4 /x Vagina repetitim observata 



Lismore(201, 206, 207, 208, 221, 226, 229). 



Gomont, I.e., p.230, PI. vii., f.l6. Very frequent in the dis- 

 trict; the smooth, rounded, uncinate tip cannot be mistaken 

 The breadth is usually 5-6/x, with cell. alt. 3-4 /x. The dissepi- 

 ments are almost invariably smooth; in No. 229, however, (a pure 

 mucous stratum) the dissepiments have the appearance of thin 

 lines, with 3-4 very distinct granules strung on them. 

 Var AUSTRALICA, n.var. (PI. xlvi., f.l4.) 



Trichomata dimensionibuset ceteris ut in forma typica, cellulis 

 autem protoplasmate spisso, globo centrali colore pallido, ubique 

 zonfi ansjustPi coloris saturatioris circumcincto. 



