198 CYSTOSPERME^. 



6. Vesiculifera CUVIERI Hass. 



Char. Filaments more slender than those of the 'preceding 

 species. Cells usually seven times as long as broad. Spo- 

 rangia oval, contained in inflated cells of an ovate form. 



Vesiculifera prolongata Hassall, in Annals of Nat. Hist., 

 X. 390. Prolifera Cuvieri Le Clerc, Mem. clu Mus. 



Hab. Pond near Louton, Essex, and again near Enfield : 

 A. H. H. 



This species is known from V. Landsboroughi by its finer 

 filaments, longer cells, and ovate form of the seed-bearing in- 

 flated cells. 



'^ The inflations of Prolifera rivularis present an oval, whose 

 great diameter is never double the small. In the Prolifera 

 Cuvieri this enlargement is so much allongated that one 

 might distinguish it almost as well by the intensity of its colour 

 as by its size. In its state of greatest contraction its great 

 diameter is triple or quadruple that of the small. The same 

 proportion, but a little less marked, is observed between the 

 grains of the two Confervce.'^ 



7. Vesiculifera lacustris Hass. 



Plate LII. Fig 1. 



Char. Filanlents nearly equal in diameter to those of V. 

 Cuvieri. Cells/)'o?w three to Jive times as long as broad. 

 Sporangium oval, sometimes almost quadrangular, solitary, 

 occasioning no very considerable enlargement of the cell 

 in tvhich it lies ; empty cell next the spore also inflated. 



Vesiculifera lacustris Hassall, in Annals of Nat. Hist., 

 vol. X. p. 390. 



Hab. In the New River reservoir, near Cheshunt, spar- 

 ingly, and other places in the vicinity : A. H. H. 



V. lacustris differs from V. Borissii principally in being al- 

 together a more robust species, and in having shorter cells. 



