316 I'RKSliWATKR ALG.E OF LISMORE DISTRICT^ 



magnis (pyrenoidibus 1) aliquot plerumque 3, vesiculis contractili- 

 bus aliquot(3-5'?), instructse. Stigma rubrum non vidi. 



Coen. diam. 30-170; iiileg. crass. 4; cell. diam. 10/x. 



Lismore (260). 



This interesting Volvox-like flagellate, all the more interesting 

 because it does not seem to belong to the green algae, is found in 

 lagoons. T first noted it many years ago, at Pott's Hill, near 

 Auburn, but it is distinctly rare. The ccenobium is hollow and 

 flaccid; even when revolving freely, it cannot retain the spherical 

 shape, but gets dented in here and there. It is formed of a 

 single layer of large, cushion-shaped cells, irregularly circular or 

 polygonal when seen from above, and nearly touching. The 

 chloroplasts are yellow-brown or yellow-green in colour, as in 

 Synura, in company with which it is often found. The proto- 

 plasmic contents of the cells are homogeneous and refractive, and 

 I have never been able to make certain of the shape of the chloro- 

 plasts. From above, the cell shows a central clear strip with a 

 parietal chloroplast, or fold of a chloroplast, on each side. There 

 are several large granules present, acting, pei'haps, as pyrenoids. 

 A number of rather large pulsating vesicles were observed in 

 each cell; the cystole and diastole are both very slow and gradual. 

 Two flagella noted, but no stigma. I have arranged this form 

 near Symira on account of the colour of the chloroplasts. 



CHLOROPHYCE^. 



Fam. ZYGNEMACE^. 



Genus Z y g n e m a Ag. 



Zygnema pectinatum ( Vauch.) A g., forma. 



Fil.diam. 26; cell. alt. 60 /x. 



Lismore (240). 



A form in which the outer sheathing membrane has been 

 ruptured, and the cells are merely adherent by the apices. It 

 seems to throw some light upon the formation of Debarya. I 

 have noted the same form from Kogarah (diam. 24, cell. alt. SO- 

 TO /x). The broken sheath may be seen at the angle of one of 

 the cells (PL xlii., f. 1). 



