HY G. I. PLAYFAIR. 313 



markable, as its forms are frequent round Sydney, and Phyma- 

 todosis also is found there locally. As in the river, forms of 

 Clostcrium (29) and Cosm,arium{^0) form the bulk of the desmid- 

 flora, accounting for exactly half, Euastrum and StaurastruTn 

 (11 each), Penium and XautJddiuin (7 each), Docidium (6), 

 Micrasterias (5), and Goiiatozyyon (4) make up the bulk of the 

 remainder, 



Bacillarieoi. — It is strange that the swamp-waters should be 

 so poor in diatoms (plentiful enough round Sydney), especially 

 considering that they bulk so largely in the river. Only 36 

 forms were met with, representing 13 genera, as against 134 in 

 the river, with 27 genera. Only 22 were common to both, viz., 

 Fimtularia{b), Nitzschia (i), Va7iheii7-ckia {S), Gomphonema {Z)^ 

 Coccotietyia (^2), Savicula, Achnanthes, Synedra, Stenopterobia, 

 and Hantzschia (1 each). It is curious and interesting to note 

 that, out of 21 forms of Aavicula (including Diadesmis), only 

 one, JVav. mutica var. Goppertiana, is common to both land and 

 river. 



Myxophycew,. — The township of Lismore is rich in these, chiefly 

 forms of Oscillatoriacece. In roadside-ditches and concrete 

 water-tables, and wherever there is a regular diibble of water, 

 mucilaginous strata are sure to form. Enmeshed in them may 

 be found certain diatoms in some quantity, sometimes, indeed, 

 in such abundance as to give to the stratum their own dis- 

 tinctive yellow-brown colour. In general also, while consisting 

 principally of one species, they contain others in lesser quantities, 

 e.g.: 



(26). Z. Lisiaorensis, L. KiUzinyii var. distincta, 0. formosa, 

 0. sjdendida va)-. amylacea, and var. limnetica, Fh. temie, Spiru- 

 liua laxissima. 



JS'itzschia palea var. debiiis, iV7 vermiculafis var. vialis, and 

 var. luinuta. 



JSav. laiiceolata, with var. ciirta and var. arenaria. 



{21).Spwuli')ta 7najo7\ 0. J'orinosa, 0. Corakiana, 0. acuminaia, 

 0. splendida var. amylacea, and var. linntetici, [0.] amphibia 

 {Spirillum filament), Spitnllum. volutaiis, S2nrulina (Joraki<ina, 

 Nitzscnia obtusa var. scalpelliformis. 



