158 CONJUGATEiK. 



dratum. Cells about five times as long as broad. Sporangia 

 ovalf and producing a slight inflation of the cells, 



Zygnema intermedium Hassall, in Annals of Nat. Hist. 

 vol. X. p. 41. 



^ Hob, High Beech ; Cheshunt : A. H. H. Pond at Rams- 

 lye ; water-course by the road side at Wadhurst ; and in 

 a wet place in Tunbridge Wells Common : Mr, Jenner, 



This very distinct species might be readily mistaken for 

 Zygnema angulatum, from which, however, it is at once dis- 

 tinguished by the inverted cells ; which cells also are longer. 



38. Zygnema diductum Hass, 



Plate XXXVII. Fig. 4. 



Char, Filaments about equal in diameter to those of Z. inter- 

 medium. Cells eight or ten times as long as broad. Spo- 

 rangia oval, producing very considerable inflation of the 

 cells in which they are lodged. 



Hab. Cheshunt : A. H. H. 



There is but little doubt of the distinctness of this species. 



39. Zygnema vesicatum Hass. 



Plate XXXVII. Fig. 5. 



Char. Filaments about equal in diameter to those of the pre- 

 ceding species, Z. diductum. Cells usually three times as 

 long as broad. Sporangia oval, j^roducing a very consider- 

 able inflation of the cells in which tliey are lodged. 



The chief difference between this and the following spe- 

 cies consists in the more considerable size of the filaments. 



40. Zygnema Jenneri Hass. 



Plate XXXVII. Figs. 6. and 9. 



Char. Filaments of less diameter than those of Z. vesicatum. 

 Cells usually three or four times as long as broad. Spo- 



