Maskell. — On New Zealand Desmidiese. 309 



front view) vary in length. Those at the ends of the segments are shortest, 

 or at least appear so from perspective effect ; so that a view of the longest 

 and most numerous rays is obtained by focussing to the middle of the frond. 



The processes, or rays, are cylindrical, slightly tapering, being some- 

 what dilated at the base. 



Endochrome bright green ; vesicles scattered. 



Extreme length in fi'ont view, including processes, ^rfj inch, without 

 processes, -gi^ inch ; length of processes in end view, fi-om centre of the star 

 to tip, 5^ inch. 



Eare. 



This is an extremely beautiful little plant, especially when seen in its 

 star shape from the end view. 



I have placed it under Didymocladon, although it differs in several par- 

 ticulars from the Enghsh species. Ealfs gives the generic characters as 

 follows : — " Frond simple, constricted in the middle, angular, each angle 

 having two processes, one lateral, and in fi-ont view nearly parallel to the 

 adjacent one of the other segment, the other superior and divergent." All 

 these characters are found in my species, and I have no doubt that it 

 belongs to Didymocladon. But, in the English plant, the end view is 

 either triangular or quadrangular, never more ; and in neither case can it 

 present anything like the star form of D. stella ; moreover, the processes 

 terminate only in two spines, whereas D. stella has three. Ealfs says that 

 the English species, D. furcigerus, is " rough with pearly granules which, 

 being arranged on the processes in transverse lines, produce a crenate 

 appearance on their margins." In D. stella the edges, as far as I can make 

 out, are distinctly crenate. 



At first sight, in end view, D. stella might be mistaken for a zygospore 

 of some other species, fi-om its stellate form. But the front view at once 

 shows this to be incorrect, and an empty frond clearly shows that it is a 

 distinct and full-grown plant. 



10. Penium, Brebisson. 



P. digitus, Ehrenberg. (E. XXV.) 



Common in spring. 



P. closterioides. (E. XXXIV.) 



Eare. 



11. Docidium, Brebisson. 



D. clavatum, Kiitzing. (E. XXVI.) 



Not uncommon. 



D. ehrenbergii, Ealfs. (E. XXVI.) 



Common. 



