202 Chaetophoraceae 



which appears to have escaped the notice of DeToni, but rather 

 than crowd it unduly into that species, it seems better to establish 

 a new species. 



Wolle's figure of Stigeoclonium nudiusculum shows consider- 

 able similarity to our plant ; it is certainly not what it purports 

 to be. 



Myxonema ventricosiun was abundant at the time noted, but 

 when sought for, less than a month afterward, none could be 

 found. The plant is so marked a form, however, that there can 

 be no doubt of its distinctness. 



6. Myxonema tenue (Ag.) Rabenh. Deutsch. Krypt. Flor. 2 2 : 



ioo. 1847 



Draparnaldia tenuis Agardh, Alg. Dec. 40. 18 14; Syst. Alg. 

 57. 1824; Icon. Alg. Eur. pi. 38. 1828-35. Hass. Brit. F. W. 

 Alg. 123. pi. 11. f. 2. 1845. Derb. & Sol. Ann. Sci. Nat. Bot. 

 III. 14: 267. PL33.J. 1-6. 1850. 



Stigeoclonium tenue Kiitz. Phyc. Gener. 253. 1843 \ Phyc. 

 German. 197. 1845; Spec. Alg. 353. 1849; Tab. Phyc. 3 : pi. 

 3. f. 1. 1853. Rabenh. Krypt. Flor. Sachs. 1: 268. 1863; 

 Flor. Eur. Alg. 3 : 377. 1868. Kirchn. Krypt. Flor. Schles. 2 1 : 

 68. 1878; Mik. Pflanz. 11. //. /, /. 19. 1891. Hansg. Prod. 

 Alg. Bohm. I : 66. 1886. Wolle, F. W. Alg. in. //. 96. f. 11. 

 1887. Cooke, Brit. F. W. Alg. 189. pi. 73. f. 3. 1883. De- 

 Toni, Syll. Alg. 1 : 197. 1889. De Wild. Flor. Alg. Belg. 44. 

 1896. 



My 'xothrix tenuis Trevis. Alg. Ten. Udin. 16. 1844. 



Tufts 5-10 mm. long, bright green ; filaments much branched, 

 slender ; main branches solitary or opposite, usually not more 

 than two pairs adjacent ; branchlets numerous, scattered or op- 

 posite, short, erect, thorn-like, tapering to an acute point or finely 

 setiferous ; cells cylindrical or slightly swollen, 7-10 fi (generally 

 8 fi) in diameter, 1—3 times as long (sometimes longer below) ; 

 branchlets 5-6 /1 in diameter at the base, cells about as long as 

 the diameter (pi. 32). 



In brooks and watering-troughs. 



Vermont : St. Johnsbury, August (643). 



Massachusetts: Melrose, May 16, 1901 (F. S. Collins, 

 4007). 



