Chaetophora 209 



Stigeoclonium longipilus Kiitz. Phyc. Germ. 198. 1845 ; 

 Tab. Phyc. 3 : pi. 7./. 1. 1853. Wolle, F. W. Alg. 115.//. 100. 

 f.2,3. pi. 102. f. 1-3. 1887. 



These three species are so similar in character that it is diffi- 

 cult to discover adequate points of distinction. We have seen no 

 American specimens that could well be identified with any of these 

 species, and as Wolle's descriptions are somewhat modified in 

 every case, we feel obliged to question his determinations of these 

 forms. Stigeoclonium longipilus minus, as issued in Phyc. Bor. 

 Am., 86 j, corresponds to Hansgirg's description, but it is doubt- 

 ful if a form like this, only 4-6 [i in diameter ought to be consid- 

 ered a variety of a species 11- 14// in diameter; this may be a 

 young stage of 5. longipilus. 



III. CHAETOPHORA Schrank, Der Naturforscher, 19: 124- 

 126. 1783; Baier. Flor. 2 : 489-490. 1789 



Rivularia Roth, Cat. Bot. I : 212-214. 1797. 



Myriodactylon Desvaux, Journ. de Bot. 2: 307. 1809. 



Thalli forming globular or elongated colonies, consisting of 

 filaments arising in a dense mass from a palmelloid base and 

 closely held together in an elastic, resistant, gelatinous substance. 

 Filaments repeatedly branched, of nearly equal diameter through- 

 out, the ultimate branchlets more or less fasciculate, often termi- 

 nating in long hyaline setae. Chromatophore a parietal band in- 

 closing one to several pyrenoids. 



Asexual reproduction by means of biciliate zoospores, formed 

 in the cells of the branchlets. Akinetes may be formed (appar- 

 ently ) in all cells. 



Inhabitants of fresh water. Type, C. globosa Schrank. [Etym. 

 yv''-'^, hair; cpopeco, to bear.] 



Until 181 2 the species which are now placed in this genus 

 generally bore the name Rivularia Roth. At that time Agardh, 

 in reviving the old genus Chaetophora Schrank, either made no 

 attempt to identify the type species or could not. 



The genus Chaetophora was founded on two species. Of these, 

 the second C. lobata, is plainly to be identified with our C. incras- 

 sata. The determination of the first or type species, C. globosa, is 

 not so simple a matter. This was based on Miiller's Conferva 

 stellaris, filamentis e basi orbiculari parallelis (Der Naturforscher 



