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FAM. IX. CYSTOSPERME.E. 



Char. Filaments simple, subulate, non-conjugating. Cells at 

 Jirst equal, subsequently here and there inflated or vesicular. 

 Sporangia formed by the union and condensation of the 

 endochrome of two contiguous cells of the same filament. 



The impression which I first entertained respecting the Con- 

 ferva contained in this family was, that it would be sufficient 

 to regard them as constituting a new genus, referrible to the 

 Conjugates already described : subsequent reflection and exa- 

 mination have, however, convinced me that they should hold a 

 higher than a generic rank, and that the characters presented 

 by them are sufficiently distinctive to entitle them to the rank 

 of a separate family. 



Their filaments are simple, slightly subulate, owing to 

 the cells growing laterally, or in diameter as well as in longi- 

 tude, usually attached, do not conjugate, are articulated or 

 jointed, and terminate in lanceolate extremities: in their young 

 condition the cells are uninflated ; subsequently, however, cer- 

 tain ones swelled up, this inflation being occasioned by the 

 transference into them of the contents of one of the adjoining 

 cells, and in these inflated cells, ultimately are formed, large 

 oval or circular bodies, similar to those of the Conjugates, both 

 in appearance and nature, and which therefore I in like manner 

 denominate sporangia. 



In addition to these essential characters of this family, the 

 Cystospermcce are distinguished by other, though less obvious, 

 not less important characteristics. The filaments are of a 

 firmer texture than those of most other Confervce, they possess 

 comparatively but little flexibility, are not mucous, and con- 

 sequently do not exhibit that glossy appearance presented 

 by so many Conferva when removed from the water, and 

 which they retain when dried upon paper ; in all which par- 

 ticulars they stand in marked opposition to that numerous and 



