62 OF THE FILAMENTOUS ALG.E. 



CHAPTER VII. 



OF THE FILAMENTOUS ALG.E. 



Although there are many more filamentous Algae than 

 those indicated below, yet for the purposes of the collector 

 we prefer to group together only the families of Confer- 

 vaceae, Zygnemaceae, and (Edogoniaeeae. All these, with 

 few exceptions, inhabit the same localities ; in many respects 

 are very similar to each other ; and are prepared for the 

 herbarium in the same way. To these may be added 

 also the genera Batrachospermum, Ulothrix (a portion only), 

 Vaucheria, Hydrodictyon, Calothrix, Tolypothrix, and Hy- 

 drurus. 



Almost all the members of this group are partial ta 

 standing water, swamps, bog-holes, and lilliputian bays, in 

 streams and ponds. The species of Zygnema are found 

 in clear cold springs, which they sometimes fill with their 

 glossy green tufts. On the other hand, Cladophora, Ulo- 

 thrix, and Vaucheria take up their abode in rivulets and 

 watercourses, where they attach themselves to stones and 

 other fixed objects, and thus safely anchored, let their 

 long wavy filaments follow each motion of the stream. 

 For specimens of Zygogonium, Hormidium, Schizogonium, 

 Chroolepus, and some of the Vaucheria?, the collector 

 must search, not the water, but the land-damp stones and 

 muddy ground, so that in their mode of life they are 

 exceptions to the great bulk of the filamentous Algae : 

 as are also the genera Chantransia, Microthamnium, Gon- 

 grosira, Chlorotylium, Coleochaete, and Chaetophora, which, 

 on account of their habit of forming close matted strata, 

 must be excluded from our ' filamentous group,' and be 

 treated of elsewhere. 



