608 SOME SYDNEY DESMIDS, 



Genus Micrastbrias Agardh. 



Micr. truncata (Corda) Breb., var. australica, n.var. (Plate xi 



fig.6). 



Forma lobulis lateralibus truncatis non inciso-dentatis, dentibus 

 ubique nondum perfecte evolutis, lobis apicalibus primo utrinque 

 dentibus singulis, turn bidentatis. 



Long 140-144; lat. 126-135; crass. 44/*. 



Coogee. 



Gf. Wolle,T.38,f 6; Delponte, T. 5, f.10; Ralfs, T.10, f 5b; and 

 Borge, Alg. Regnell. T.5, f.18. 



Var. decemdentata (1 = 3Iicr. decemdentata Nag., Gatt. Einz. Alg. 



T.6, f.2). 



Long. 88-120; lat. 90-126; crass. 40 M . 



Auburn (12), Collector, Botany, Coogee (4, 13). 



Var. laticipiformis, n.var. (Plate xi., figs. 8-9). 



Forma ad Micr. laticipem Nord., (Desm. Braz. Cent. T.2, f. 14) 

 valde accedens. 



Long. 102-108; lat. 108-115; crass. 40 M . 



Collector, Fairfield (84). 



Var. laticipiformis and var. decemdentata are both stages of 

 growth. I do not feel certain whether the latter should be con- 

 sidered as identical with Micr. decemdentata Nag. Nageli gives 

 diam. 40, Delponte and Lundell 50, ours are 90-1 26/x. Wolle 

 indeed quotes American forms at diam. 83-110, but the illustra- 

 tions he gives, T.33, f.5-6, show that his specimens belong to 

 Micr. truncata var. decemdentata mihi, and not to Nageli's plant, 

 unless they are one and the same. An excellent specimen of 

 /3 V psaliensis Cleve (Lund. T.l, f.7), which I have figured in rny 

 notes, measures 88 x 110, but Lundell gives 52 x 52^. 



Genus Euastrum Ehr. 



Eu. quadratum Nord., Desm Braz. Cent. T.2, f. 10; subsp. inermius 



Nord., var. perornatum, n.var. (Plate xii., fig.l). 



Forma major, paullo profundius incisa, lobis intermediis multo 



(lobo apicali paribus) productis, spinis marginalibus acutioribus, 



