604 SOME SYDNEY DESMIDS, 



found in quantities, sometimes even forming a pure gelatinous 

 crust on the surface of the water. More spasmodic in their 

 appearance are Tetm. laevis, Tetm. Brebissonii, Xan. C oogeanum, 

 CL striolatum, Cl. Cynthia, CI. lunula, CI. praelougum var., 

 Sp)iro. obscura, Sp. condensata, PI. nodosum, Pen. cucurbita, Pen. 

 navicida, Cos. tinclum, Cos. orthopunclulatum, Cos. pseud o- 

 pyramidatum vars., Cos. mesoleium, Cos. amoenum vars., Cos. 

 subspeciosum, and Hyal. hians. 



Genus Closterium Nitzsch. 



Cl. lanceolatum Kiitz. /3 coloratum (Klebs). (Pl.xi., fig.l). 



CI. lunula /3 coloratum Klebs, ex parte, Desm. Ostpreuss. T.i.,. 

 f.lc,d. 



Forma, a fronte visa, ventre omnino plana, apicibus subtrun- 

 catis interdum paullulo reflexis. A latere late-fusiformis, apicibus 

 subtruncatis; ex obliquo ut a cl. Ralfs, T.28, f.lb, delineata sed 

 apicibus subtruncatis. Endochromain laminas longitudinales circ. 

 10-12 ordinata, nucleis amylaceis 5-6 in quaque semicellula in 

 seriem unicam dispositis. Membrana achroa vel luteola. 



Long. 162-270; lat. 25-45; crass, ad 44^. 



Coogee, Centennial Park (71). 



If the amylaceous nuclei are allowed to have any weight at 

 all in determining the species, this form should be arranged 

 under Cl. lanceolatum rather than with Cl. lunula. Klebs. I.e. 

 p. 6, has evidently mixed up a typicum and /3 coloratum in the 

 dimensions. According to his notes, those with one series of 

 nuclei range from 145 x 20 to 286 x 41, and those with several 

 series from 256 x 44 to 555 x 88, in each case the usual doubling 

 in size. Nordstedt records this form from New Zealand at about 

 the higher figure. The three specimens I have seen at different 

 times also give a range in size approximating to that of Klebs 

 for /3 coloratum. Ends subtruncate, not pointed. Cells fusiform 

 in side-view, and in three-quarter face exactly the shape of Cl. 

 lanceolatum as figured by Ralfs in Brit. Desm. T.28, f.lb, but 

 with subtruncate tips. 



