30 SIPHONACE^. 



often elongate, spongy stipes, and a brushlike habit, not unlike that of a Penicillus ; 

 and few algologists will question its claim to generic distinction. I am not quite sure 

 that I do well in associating the following species in the same genus ; but I know not 

 where else to place it. unless indeed in Vaucheria. The specimens, however, appear to 

 be scarcely mature ; there is a resemblance in the colour and substance, and the habitat 

 is not dissimilar ; and I am willing to think that more advanced specimens might 

 exhibit more of the spongy stipe which forms the most tangible character of this genus. 

 The fruit has not been observed. 



1 . Chlorodesmis ? V auchericeformis ; stipes obsolete ; fronds subsessile, comoso 

 penicillate, fastigiate, dark-green, composed of innumerable, slender, dichotomous, ex- 

 ceedingly lubricous and subgelatinous, unicellular, cylindrical filaments ; apices equal, 

 level-topped, obtuse. (Tab. XL. C.) 



Hab. On stones, at Brown's Wharf, Key West, W.H.H. (v. v.) 



Stipes obsolete, consisting in a bulbous mass of interlaced, branching fibres, which 

 throw up the erect and free filaments of which the frond is composed. These filaments 

 form dense pencil-like tufts, about an inch high, and perfectly fastigiate. They are 

 exceedingly slender, cylindrical, of equal diameter throughout, dichotomous, obtuse, 

 gelatinoso-membranaceous, soft, and very lubricous, and filled with a dense, deep-green 

 endochrome. Each filament is strictly unicellular, without articulation or constriction. 



Plate XL. C. Fig. 1. Chlorodesmis Vaucheiiceformis ; the natural size. Fig. 2. 

 Portion of one of the branching unicellular filaments. Fig. 3 and 4, small portions of 

 the same ; the latter figures magnijied. 



VL VAUCHERIA. D.C. 



Fronds densely csespitose, and somewhat interwoven ; each consisting of a single, 

 irregularly branched, unicellular cylindrical filament. Cell-wall very thin and delicate. 

 Endochrome granular. Sporangia lateral, on the sides of the branches. Antheridia 

 cylindrical, hooked, accompanying the sporangia. 



The greater number of species of this genus occur in freshwater ponds, ditches, and 

 streams, and probably several may yet be found in North America. I have received 

 from Mr. H. W. Ravenel of South Carolina a specimen of a Vaucheria apparently 

 allied to V. dichotoma, but not in a state to be recognised. It was found floating in 

 limestone waters. Dried specimens of this genus are rarely of any use, as the specific 

 character is generally lost in drying. 



