BY G. I. PLAYFAIR. 607 



Long. 198-420; lat. 13-18; lat. apic. 3J-5/*. 



Botany (17), Centennial Park (6), Coogee (4, 13). 



These three forms are quite distinct. The last is not uncom- 

 mon in localities where the type is found, but on no specimen 

 have I ever seen the slightest trace of striae. It is not too 

 much like West & West's figure, which more resembles var. 

 rectum, but I do not see what else it can be. 



Genus Penium, Breb. 



Pen. spirostriolatum Barker. (Plate xi , fig.5). 



Pen. margaritaceum y punctata Ralfs, p.149; = Pen. margari- 

 taceum /3 elongatum Klebs, ex parte, Desm. Ostpreuss. T.2,f. 18a,b; 

 — Pen. gracillimum Playf. (Proc. Linn. Soc. N. S. Wales, 1907, 

 p. 168) sec. G. S. West in Nord., Index Desm. app. p. 64. 



Endochroma semper in partes 4 transverse divisa, in laminas 

 longitudinales angustissimas 8-10 (visis 5-6) disposita, nucleis 

 amylaceis 6 in quaque semicellula. 



Long. 90-190; lat. I2J-18/*. 



Coogee (4,13), Botany. 



This desm id is fairly common here, but none that I have seen 

 have had the stria? arranged spirally. It would appear, however, 

 that they rarely are. They seem to be rows of scrobiculse or 

 excavations close together upon the inner surface of the mem- 

 brane, or coalesced together to form a groove. I am supplying 

 another figure, that (as Pen. gracillimum) given before not being 

 typical. The marginal denticulations are not always present. 

 The semicell is divided up very often by a number of sutures, 

 and the denticulations sometimes present are caused by incrassa- 

 tion of the cell-wall at one or more of these. The membrane is 

 only rufescent when old, and then very slightly. However many 

 sutures or pyrenoids there may be, the endochrome is always 

 interrupted in the middle of the semicell, though not generally 

 so plainly as in Klebs' figure. This fact is mentioned by Ralfs, 

 I.e., but his statement that the endochrome has no longitudinal 

 fillets is not correct. 



