206 Chaetophoraceae 



This species is very similar in the character of the terminal 

 branching to Stigcoclonium fasciculare Ki'itz. (not Wolle), but it 

 differs so much from that form in the long cells of the main 

 branches that it must be considered as distinct, at least until 

 further evidence as to Kiitzing's species is obtained. 



Great diversity in the density of the branching may be seen 

 even in a single tuft, and from this circumstance one might suspect 

 this to be an abnormal form of some other species. Because, 

 however, it has maintained in character in the same station, 

 under changed conditions in successive seasons, it has seemed 

 impossible to refer it to any other species. 



1 1 . Myxonema attenuatum sp. nov. 



Tufted, or forming dark green lubricous skeins, 10 mm. to 4 

 dm. long ; dichotomously divided near the base into numerous 

 long, slender filaments, sparsely branched above ; branchlets short, 

 spinescent or flagelliform, solitary or 2-3 arising at the same point, 

 less often opposite, tapering into an acute point or into a very 

 finely attenuated seta ; cells cylindrical, 5-7 fi in diameter, mostly 

 2—5 times as long , chromatophore thin and somewhat broken 



{Pl- 35)- 



In running water of watering-troughs. 



Vermont : St. Johnsbury, March to November (642, 646, 

 667, 670, 685). 



Connecticut: Thomaston, February to May (522, 540B, 



547)- 



This species is capable of growing to a greater length than is 



recorded for any other species in the genus. It forms fine silken 

 tufts on the bottom or sides, and long skeins in the overflow on 

 the outside of iron or wood watering-troughs. Sometimes it 

 stretches in fine cobweb-like strands across a tub just below the 

 surface of the water, and resembles in appearance a fine Ulothrix. 

 Usually one does not see the character of the basal branching ex- 

 cept in the shorter tufts. 



The plant was fully grown in February (although it was not 

 visible in December) and seemed to disappear from the two Con- 

 necticut stations where it was observed, before summer. In Ver- 

 mont it is probable that it was growing from early spring until 

 destroyed by ice in autumn. 



