Fresh-ivater Algce of Canada. 339 



which immediately precedes it. Both of them are highly mucous to 

 the touch, and their lubricity chiefly arises from the presence of in- 

 numerable lashes or ciliform appendages which terminate their 

 branches. They likewise agree in habit, dwelling for the most 

 part in fresh, pure water, in spring-wells in which there is a con- 

 stant current, and upon rocks and stones in the shallow and shel- 

 tered parts of rivers and streams. It is doubtful whether a sepa- 

 rate family should be made of this group of genera. The genus 

 Drapemaldia which it embraces, has certainly in its mature state 

 a close resemblance to the Batrachosperms, while in its early stages 

 it approximates to the character of Ch&tophora. The only point 

 in which the Batrachosperms differ materially from this family is 

 in the verticellate fronds or filaments of the former ; but it may 

 be doubted whether these are more than mere generic distinctions. 

 Our idea is that Vaucher's arrangement in this respect is much to 

 be preferred to that adopted by Hassall. 



Genus I. Drapernaldia, Bory. 

 Char. — Filaments free, not immersed in a gelatinous matrix. 

 Hassall's Hist. Brit. F. Algce, p. 118. 

 Bory, in his Annates du Museum, dedicates this genus to Dra- 

 pernaud, a distinguished but modest naturalist, who took great 

 delight in the study of the Coufervse. 



The mode of its reproduction is simple. If a specimen be ex- 

 amined in a young state, the filaments will be found to be made 

 up of cylindrical cells ; but by and bye the green granules which 

 the cells contain, become enlarged and swell up the cells, so that 

 the filaments assume a beautiful beaded form, which gives a 

 most distinct character to the frond. This inflation is indicative 

 of the period of reproduction. The cells soon rupture, and the 

 zoospores escape through the aperture, and after swimming about 

 for an hour or two become fixed, and germinate by the elongation 

 and division of the cells. 



Of this genus we find the following species in Canada : 

 I. Drapernaldia plumosa, Ag. 

 Char. — Frond, gelatinous. Filaments gracile, elongated. Branches 

 subpinnate. Tufts elongated, scattered, approximate to the 

 branches, ciliated. 



Hassall's Hist. Brit. F. Algce, p. 121, Plate, XII, fig. 1. 

 Hob. — Quiet deep and clear pools or spring-wells ; fine specimens 

 collected on the Mountain, and in the fields at Mile End toll 

 bar, Montreal. 



