206 CHAETOPHORACEAE 
This species is very similar in the character of the terminal 
branching to Stigeoclonium fasciculare Kitz. (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 Kützing’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. 
11. 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 » in diameter, mostly 
2-5 times as long, chromatophore thin and somewhat broken 
(Pl. 35). 
In running water of watering-troughs. 
VERMONT : St. 7 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. 
