440 



SUPPLEMENT. 



ZYGNEMA INSIGNE Hass. 

 Plate GUI. Figs. 1, 2. 



Char. Filaments of considerable size. Cells four or Jive 

 times as long as broad, inverted. Spires three, lax, in- 

 distinct. Sporangia oval, acute, producing considerable 

 inflation of the cells in which they are placed. 



Hab. Ponds at Wadhurst, near Tunbridge Wells, and 

 Iden, near Rye : Mr. Jenner. 



This fine species is rendered particularly interesting from 

 the circumstance of its being the only Zygnema with three 

 spires having inverted cells, all other species thus constructed 

 which have hitherto been discovered possessing, with but one 

 exception, in which there are two threads, only a single 

 spire. 



The filaments are about equal in size to those of Zygnema 

 rivulare, from which it is at once distinguished by its inverted 

 cells. 



The credit of the discovery of this species is entirely due to 

 Mr. Jenner. 



LYNGBYA FUSCO-PURPUREA Hass. 

 Plate VIII. Figs. 1, 2. 



Char. Filaments of considerable size, forming a brownish 

 green or purple stratum, glossy. Endochrome at first 

 homogeneous, subsequently granular. Granules./??^ about 

 Jive in each cell. 



