192 SOME NEW OR LESS KNOWN DESMIDS FOUND IN N. S. WALES, 



St. apiculatu7n Breb., in Cooke, T.49, f.2, which have spines 

 instead of processes; the latter also lacks the lines of minute 

 puncta-granules. 



St. assurgens Nord., Alg. N. Z. p.37, T.4, f.8. 



Long. 44, 50, 50, 52; lat 84, 87, 92, 80; crass. 20, — , 16, 21^. 



Botany, Centennial Park. 



Formae immaturae. (T.v. f.31). (See note below). 



Long. 36, 40, 42, 42, 42; lat. 50, 50, 50, 52, 70; crass. 18, — , — , 

 15,-;.. 



Botany, Centennial Park. 



All the Australian specimens noted differ a little from Nord- 

 stedt's figure, I.e., in the spines at the apex of the rays, which, 

 together with the central swelling in end view, are, as he says, 

 characteristic of the species, even in its young forms. The spines 

 are not sharp-pointed, but blunt and rounded at the tip; the 

 lower (for there are only two prominent) always continues the 

 lower edge of the ray, while the upper widely diverges upwards 

 and outwards. The upper edge of the ray is just a little retuse 

 behind the spines, giving a recurved appearance to the end. If 

 the cell be tilted a little, eight verrucae come into view, some- 

 times tipped with long spines. A curved row of five granules 

 may be seen in front view running round the base of the central 

 tumour and some way down each ray. Neither these nor the 

 verrucae are conspicuous in the youngest forms. In end view a 

 minute spine can be seen at the base of the terminal spine, on 

 each side; in front they are only visible as granules. The youngest 

 forms are sometimes very convex on the back, more so than in 

 the figure, the rugae smoothed down, and the basal portion of 

 the semicells more or less globose. 



I consider St. indentatum West, Fr. Alg. Ceylon, T.22, f. 10-12, 

 to be an immature form of assurgeiis. He gives size 34-39 x 52-76, 

 crass. 17/x, which tallies exactly with the size of our immature 

 forms given above. The same applies to St. hicorne Haupt., in 

 Rac, Desm. Ciast. (from the Centennial Park) T.2, f.8; size 

 42 X 72/x. 



