300 TUFTS COLLEGE STUDIES, VOL. II, No. 3 



chromatophores, remind one of a Draparnaldia, and seem to 

 characterize the species sufficiently. 



6. S. TENUE (Ag.) Kiitzing, 1843, p. 253; Wolle, 1887, p. 

 no, PL XCVI, fig. ii ; Wittr. and Nordst., Alg. Exsicc., No. 

 1429; Myxonema tenuc Hazen, 1902, p. 202, PL XXXII. 

 Tufts up to i cm. high, bright green ; filaments slender, 7-10 p- 

 diam. below, 5-6 p. in the ramuli ; cells cylindrical or slightly 

 swollen, 1-3 diam. long; in ramuli about as long as broad; 

 main branches solitary or opposite, not many pairs together; 

 ramuli numerous, scattered or opposite, short, erect, tapering to 

 an acute point or a very slender seta. Mass., Conn., Vermont, 

 N. Y., Cal. Europe. 



A slender, loosely branched species, forming a transition from 

 the opposite-branching 6". lubricum group, to the less luxuriant, 

 alternately branched species. 



7. S. THERMALE A. Braun in Kiitzing, 1849, p. 353; 1853, 

 PL II, fig. 4 ; Wolle, 1887, p. in, PL XCVI, fig. i ; Myxonema 

 thermale Hazen, 1902, p. 203. Filaments with somewhat creep- 

 ing base, freely branching, ramuli distant, alternate or opposite, 

 erect or patent, tapering to a point ; cells 7.5-12 p. diam. below, 

 1-2 diam. long ; in ramuli 3-5 diam. long. 



A plant of warm springs and hot water escapes from mills, etc.' 



8. S. NANUM (Dillw.) Kiitzing, 1849, p. 354; Wolle, 1887, 

 p. 112, PL XCVI, fig. 10 ; P. B.-A., No. 867; Myxonema 

 nanum Hazen, 1902, p. 204. Two to three mm. high; branch- 

 ing alternate, ramuli tapering, obtuse or short-pointed ; cells 

 6-8 /A diam., 1-2 diam. long. Neb., So. Dakota, Cal. Europe. 



A not very strongly characterized species ; perhaps a state of 

 some other, but at present there is no evidence to connect it 

 with any other form. As P. B.-A., No. 1375, there was dis- 

 tributed, as forma subsimplex Collins, a form from California, 

 with filaments even shorter than in the type and hardly at all 

 branched. 



9. S. aestivale (Hazen) nov. comb.; Myxonema aestivale 

 Hazen, 1902, p. 205, PL XXXIII, figs. 1-3; P. B.-A., No. 

 1074. Light green, forming dense tufts up to i cm. high ; base 

 palmelloid ; branching alternate or dichotomous, erect ; main 

 filaments 7-9 p. diam., rarely more; cells 2-6 diam. long below, 

 about as long as broad above, thin-walled, somewhat swollen ; 

 ramuli few, scattered or somewhat approximate near the sum- 

 mit, frequently attenuate into fine setae. Growing in dense tufts 

 along the edges of troughs and fountains. Vermont, Mass., 

 N. Y., Conn. . 



