306 



FAM. XVII. PALMELLE^E. 



Char. Frond consisting of a gelatinous colourless fluid, in 

 which are immersed numerous globules, containing the co- 

 louring matter. 



45. PALMELLA Lyngb. 



Char. " Frond mucous, indefinite, enclosing hyaline globules, 

 in which the colouring substance, continuous, and never 

 granular, is situated. Granules Jirst evolved in the 

 mucous substratum of the frond, at length constituting new 

 globules." Meneghini. 



Derivation. From TraX^os, vibration ; in allusion to the 

 gelatinous nature of the frond. 



" This genus differs from all the other genera of Nosto- 

 chinece, especially in its frond, which, from the beginning, is 

 indefinite. In other species the frond preserves its defined 

 form during the entire course of its existence, or at least in the 

 beginning describes a certain form with peculiar limits. But 

 in this, the frond never can possess a definite form, on account 

 of the nature of its generation and evolution ; for the globules 

 living in the mucous substratum of the frond, otherwise 

 very similar to those of other Nostochinece, differ as much 

 as possible from all others, in the fact of the colouring matter 

 in them never becoming granular, and that, because the gra- 

 nules from which new globules proceed are neither evolved 

 nor undergo evolution in the interior of the maternal globules ; 

 for these are either altogether resolved into mucus, or pour 

 out the mucous substance which they contain, which sub- 

 stance not being covered with an involucre, is indefinitely 

 diffused, and is circumscribed only by external circum- 

 stances. But in this mucosity minute punctated points or 

 granules appear, which little by little are evolved, and at 

 length attain to the dimensions of the parent globules. The 



