394 Mr. Hassall's Notices of British Freshwater Conferva. 



In the New River Reservoir, arid other places in the vici- 

 nity of Cheshunt. 



Vesiculifera bombycina. Filaments more slender than those 

 of the preceding species ; cells fully four times as long as 

 broad ; spores spherical, contained in inflated cells, which 

 have their sides somewhat compressed. Three or four in- 

 flated cells sometimes occur in juxtaposition. 

 Common, Cheshunt. 



Vesiculifera angusta. Filaments scarcely equal in diameter to 

 those of Vesiculifera bombycina, somewhat mucous ; cells 

 usually about three times, but sometimes nearly four times 

 as long as broad. 



The joints of this species are somewhat inconspicuous from 

 the fineness of the filaments, as well as from the circumstance 

 of the endochrome filling the entire cavity of the cells. Al- 

 though I have not seen any of the cells inflated, I yet regard 

 it as a Vesiculifera, on account of the contraction of the 

 joints in drying, and the absence of gloss on the filaments. 

 This species is by no means uncommon, and has probably 

 been confounded with V. bombycina. 



Cheshunt and other places ; Ilfracombe, Mr. Ralfs. 



Vesiculifera pygmcea. Filaments about equal to those of V. 



bombycina ; cells rather longer than broad, joints strongly 



marked. 



This species resembles greatly Sphceroplea vermicular is, but 

 has longer cells and more strongly marked joints. It often 

 adheres to the roots of trees which grow in the water. 



Cheshunt ; Penzance, Mr. Ralfs. 



Subgenus. 

 Char. Filaments attenuated, brittle ; joints strongly marked, 

 when dry somewhat contracted ; filaments lustreless ; spores 

 placed in inflated cells, two of which enter equally into the 

 formation of each inflation. 



Vesiculifera composita. Filaments somewhat slender, very 

 fragile, of a dark chocolate colour ; cells rather longer than 

 broad ; spores circular, placed in inflated cells of the same 

 form. 



So remarkably does this species differ from other Vesicu- 

 lasperms, that I should have hesitated to have associated it 

 with that group, had I not discovered the vesicles upon the 

 species, of which a definition is given above. It agrees with 

 other Vesiculiferce in having attenuated filaments and strongly 

 marked joints, but, on the other hand, it is remarkably distin- 



