Maskell. — On New Zealand Desmidieae, 313 



slightly outwards ; no median suture ; fillets several, but obscure, some- 

 times not visible ; vesicles numerous, scattered. The empty frond is 

 colourless, with no strife. The globule of moving granules is very small, 

 and situate quite close to the tip. 



Common in spring. 



This is a fine handsome plant, and I think not agreeing with the Euro- 

 pean species. Those which in form approach nearest to it are C. ehren- 

 hergii, Meneghini, C. leibleinii, Kiltzing, and C. moniliferum, Bory ; but it 

 differs from all in the absence of median inflation of the inner margin, which 

 is conspicuous in all three, especially the first. C. ehrenhergii also has con- 

 spicuous longitudinal fillets, and the ends are thick and round. C. monili- 

 ferum is too small, and its vesicles are in a single row ; and the same may 

 be said of C. leibleinii, otherwise this species might agree almost wholly with 

 my C. selencBimi. However, the outward bending of the extreme tip of C. 

 selencBum, mentioned above, would seem to separate it from all other species 

 with acute ends. This bending is very shght, and best distinguishable in 

 the empty frond, but I find no mention of any such character in the Euro- 

 pean species, with the exception of C. turgidium, Ehrenberg ; but in that 

 plant the bending is very conspicuous, the ends are thick and round, and 

 the whole plant different. C. decussatwn, Klitzing, is striated. 



Length of chord of arc, Jg- inch ; breadth at the middle, -g-i^y to ^hs 

 inch ; from tip to middle along the frond, -^q inch, 



C. leibleinii, Kiltzing. (E. XXYIII.) 



Fairly common. 



C. diancB, Ehrenberg. (E. XXVni.) 



Common. 



These two species may be easily mistaken. Ealfs considers them pro- 

 bably identical. I have judged by the absence or presence of a median in- 

 flation. 



0. didijmotocum, Corda. (E. XXVIII.) 



Eare ; from Fernside. 



C. striolatum, Ehrenberg. (E. XXIX.) 



Not common. 



C. didymotocnm has no striae ; C. striolatum has numerous and close but 

 distinct striae. Both species have a varying number of median sutm-es. 

 Both are somewhat dark-coloured ; indeed 0. didymotocum is at times almost 

 black. 



C. jimcidum, Ealfs. (E. XXIX.) 



Common. 



C. setaceujn, Ehrenberg. (E. XXX.) 



Fairly common. 



40 



