ZYGNEMA. 151 



Rackham, near Pulborougli : Mr. Jenner. Dolgelley : 

 Mr. Ralfs. Parkind : Major 3Iartin. 



This is a very distinct, as well as common species; that 

 wliicli I regard as a variety of it occurs at Wanstead Flats, 

 Essex, in which the filaments are somewhat finer, the cells 

 considerably longer, and the sporangia smaller. This may 

 be distinct. 



24. Zygnema longatum Hass. 



Plate XXXI. Figs. 3, 4. 



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

 ventricosum. Cells usually eight times as long as broad. 

 Sporangia not jiroducing any inflation of the cells, in 

 which they are formed. 

 Conferva punctalis Miiller, Flor. Dan. pi. 1. no. 1. Con- 

 jugata longata Vaucher, Hist, dcs Conf. pp. 71, 72. 

 plate 6. fig. 1. ; Dillw. t. 3. upper figure in part? Z. 

 (Bquale Hassall, in Annals of Nat. Hist. vol. x. p. 39. 

 Hah. Cheshunt, rare : A. H. H. In a pond between 

 Pembury and Lamberhurst Quarter : Mr. Jenner. 



I have but little doubt of the correctness of the synonymcs 

 quoted ; the cells are never inflated. " II n'y a rien de jjIus 

 elegant ct de plus gracieux au microscope que cette jolic 

 conjuguee." — Vaucher. 



25. Zygnema inflatum Hass. 



Plate XXXII. Figs. 6, 7, and 8. 



Char. Filaments of 7nuch less diayneter than those of Z. sub- 

 ve7itricosum. Cells usually four, five, or six times as long 

 as broad. Sporangia elongated, and lodged in cells ichich 

 become considerably inflated for their reception. 



Conjugata inflata Vaucher, Hist, dcs Conf. p. 68. plate 5. 

 fig. 3. Zygnema varians Hassall, in Annals of Nat. Hist, 

 vol. xi. p. 431. 



