BY G. I. PLAYFAIR. 179 



the above, however, were clearly Xan. octonarium, as was shown 

 in every case by the size and the central incrassation. Nordstedt 

 (I.e.) gives 118 X 78/x over all as the size of New Zealand speci- 

 mens, spines up to 20;:^ long. It is evident that the number of 

 spines is not to be relied on for identification. Where I noted 

 the end view it has been perfectly and broadly elliptic, not at all 

 hexagonal or with truncate apices — this perhaps on account of 

 the specimens being immature. The incrassation is on the inner 

 side of the membrane, and visible in front view. 



Xan. Coogeeanum, n.sp. (T.iv. f.6-7). 



Xan. magnum, latum, oblongum, medio sinu linear! exti'or.sum 

 ampliato constiictum. Semicellulae subhexagonae, supra l^asin 

 rectangulares; lateribus levissime retusis; angulis inferioribus 

 fere rectis; lateribus e basi lato verticalibus, a medio semicellulae 

 ad apicem converijentibus; apicibus latis, truncatis, processibus 

 8 concentrice ordinatis, instructis; angulis basalibus et medianis 

 processibus singulis praeditis; infra marginem semicellulae 

 insuper, processibus biuis et denbibus acutis singulis, supra 

 isthmum etiam dente unico, ornatae; processus omnes breves, 

 validi et bitidi. A latere visae suboblongae, basi rotundato- 

 truncatae; a vertice late-ellipticae. Membrana dense punctata 

 interdum crassa. 



Long. 69-84; lat. 51-60; lat ap. 35-1:2; long. proc. ad. 12; crass. 

 36-40/z. 



Coogee. 



This species belongs to a small Australian group in which the 

 semicell shows a tendency to be three-lobed, the end lobe more 

 or less drawn out. The apex is furnished with processes 

 arranged in a circle, and the lateral lobes with processes in pairs 

 extending in towards the centre of the semicell. Cf. Xan. bi/ur- 

 catum Borge, in Bailey, Bot. Bull, xv., T. 1 4, f.6; Xan. ( Eu. ) 

 multigihherum Nord., Fr. Alg. N. Z. T.3,f.2; and Xan. pn/cherri- 

 mum, below. 



