BY G. I. PLAYFAIR. 489 



Forma mixta. — var. stellinum et var. gemmescens (infra). 

 Long, c.proc. 34, s.proc.32; lat. stell. 98, lat. gemmesc. 7'2fi. 

 Collector. 



Var. PLATYCERUM(Josh.). (Pl.xii., f.9). 



Long. 30; lat. corp. 16, c.proc. 76; isth. 10/x. 



Sydney "Water-supply. 



A six-rayed form; only an optical section is given of all the 



forms. Compare Joshua, Burm. Desm., PI. 24, f.2. Whatever 



the author intended fig.l to be, it can be accepted only as the 



end-view of a four-rayed form. Cf. Borge, Austral, siissw., T.2, 



f.23. 



Var. DENTATUM, n.var. (Pl.xii., f.lO). 



Forma dentibus triangulis singulis vel aculeis validis singuh's 

 in vieem processuum superiorum instructa. Long, centr. 30-40; 

 lat. corp. 17-18, c.proc. 64-76; isth. 10; long.spin. ad 12fx. 



Sydney Water-supply. Cum priori rarius. 



Fig. 10a shows the spine from another specimen, indicating a 

 second mode of development. Granules form on either side of 

 the spine, and as these grow outwards into spines the upper part 

 of the original falls in and is drawn out flat. 



Var. GEMMESCENS, n.var. (Pl.xii., f.ll). 



Forma processibus superioribus brevissimis, glabris, bifidis; 

 apicibus cellularum interdum productis truncatis. Long.centr. 

 36; lat.c.proc. 80/^. 



Collector. 



Var. SUBGLABRUM W. & G. S. West, forma. (Pl.xii., f.l2). 



Forma processibus superioribus perfecte glabris, vel denticula- 

 tionibus singulis utrinque munitis, Long.centr. 60; lat.c.proc. 



100;.. 



Collector. 



Var. ASPERUM, n.var. (Pl.xii., f.l3). 



Forma denticulationibus processuum psene in aculeos protractis; 

 processibus leviter inflatis. Long.centr. 60; lat.c.proc. 105/.. 

 Centennial Park. Rarissime. 



