188 SOME NEW OR LESS KNOWN DESMIDS POUND IN N. S. WALES, 



Auburn, Sydney Botanical Gardens, Mosman. 

 A triradiate form is believed to have been noticed. Cf. West, 

 Alj^. Madag. p.79, T 9, f.lO-ll. 



St. Rosei, n.sp. (T.v. f.6). 



St. mediocre, medio vix constrictum. Semicellulae ohlongae, 

 dimidio latiores (sine proc.) quam longae, dorso levissirae concavae 

 fere planae; lateribus e basi baud diveigentibus, angulis superi- 

 oribus fissis et in processus binos, inferiores horizontales, superi- 

 ores fere verticales productis; processibus longis (diametro semi- 

 cellulae aequa libus) gracilibus, glabris, denticulationibus medianis 

 magnis singulis (utroque latere) ornatis; apicibus bi-aculeatis. A 

 vertice visae triangulares, angulis in processus longos glabros 

 (denticulationibus nuUis) singulos protractis, apicibus bi-aculeatis, 

 apud quemque angulum proce.^su altero. Membrana laevi. 



Long. c. proc. 50; lat. c. proc 62; long. s. proc. 20; lat. s. proc. 

 15^. 



Rose's Lagoon, Collector. 



It is curious that the denticulation on the side of the processes 

 should be visible in front view only; in end view the processes 

 are quite smooth. The nearest species to this seems to be St. 

 cruciforme mihi, T.iv. f.l7. Cf. also St. hihracMaUnn Reinsch, 

 var. cyathiforme West, Alg. Madag. T.8, f.28a. That, hovyever, 

 is only a biradiate form. 



St. moniliferum, n.sp. (T.v. f.7). 



St. parvum, paullo longius quam latum, medio sinu minuto vix 

 constrictum. Semicellulae ohlongae, parte inferiore glabro; 

 lateribus e basi verticalibus, rectis; sursum dilatatae, ellipticae, 

 dorso late rotundatae ; angulis lateralibus obtuse-rotundatis 

 seriebus 4 transversal ibus granulorum ornatis, sine aculeis vel 

 granulis apicalibus, supra isthmum series granulorum unica. A 

 vertice semicellulae triangulares, lateribus leviter concavis, 

 angulis obtusis, seriebus 4J transversalihus granulorum ornatis. 



Long. 34-36; lat. 27-29; lat. has. 11/x. 



Botany. 



