Maskell. — On New Zealand Desmidieae. 307 



C. undulatum, Corda. (E. XV.) 



Not uncommon. 



The difference between these two species is, generally, that the segments 

 of C. crenatmn are longer than broad, those of C. undulatum broader than 

 long ; but, in order to thoroughly distinguish them, the sporangia should be 

 observed. Those of C. undulatum have long spines divided at the apex ; 

 those of C. crenatum short spines. 



G. botrytis, Bory. (R. XVI.) 



Not uncommon. 



But I cannot make sure of this plant. My specimens may really belong 

 to the next species, from which C. botrytis differs only in the slightly trun- 

 cate ends, a scarcely satisfactory character. 



C. margaritiferum, Turpin. (E. XVI.) 



Common. 



A very handsome plant, somewhat variable in size. The " swarming " 

 motion of the granules is often very conspicuous in this and the last species. 



C. broomeii, Thwaites. (E. XVI.) 



Not uncommon. 



Chiefly distinguishable from the last by the compressed or straight ends. 

 The slight inflation at the middle, in the end view, is often difl&cult to make 

 out in the live plant. 



C. phaseolus, Brebisson. (E. XXXII.) 



Eare. 



The characteristic feature is the very small circular inflation at the 

 centre of the segments seen only in the end view. The frond is extremely 

 minute, length y^-y inch, breadth -g^-^, according to Ealfs. 



C. moniliforme, Turpin. (E. XVII.) 



Very rare. 



C. granatum, Brebisson. (E. XXXII.) 



Very rare. 



C. pyramidatum, Brebisson. (E. XV.) 



Eare. 



a ornatum, Ealfs. (E. XVI.) 



Doubtful. Not uncommon in spring. 



I have not been able to satisfy myself as to this species. Some speci- 

 mens have undoubtedly the truncate projection beyond the margin, but I 

 have not made out the linear arrangement of the puncta on the empty 

 frond. 



8. Staurastrum, Meyen. 



8. dejectum, Brebisson. (E. XX.) 



Common, 



