440 



SUPPLEMENT. 



Ztgnema insigne Hass. 



Plate cm. Figs. 1, 2. 



Char. Filaments of considerable size. Cells four or five 

 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. 



Hah. Ponds at AVadhurst, 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 tliere are two threads, only a single 

 sj)ire. 



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 rUSCO-PURPUEEA Hass. 



Plate VIII. Figs. 1, 2. 



Char. Filaments of considerable size, forming a broionish 

 green or purple stratum, glossy. Endochrome at first 

 homogeneous, subsequently granular. QvsawXQsfeio, about 

 five in each cell. 



