THE GREEN ALGAE OF NORTH AMERICA 299 



Appearing like a small and delicate state of S. lubricum, but 

 considered by Hazen, who collected it in many localities, as a 

 well defined variety. 



2. S. AMOENUM Kiitzing, 1845, p. 198; Wolle, 1887, p. 113, 

 PI. XCVIII, fig. 4; P. B.-A., No. 1073; Myxonema amoenum 

 Hazen, 1902, p. 199, PI. XXIX. Light green, tufted, up to 10 

 cm. long ; filaments much branched, after the type of ^. lubri- 

 cum ; the ramuli tapering and pointed but rarely setiferous ; 

 cells in main branches cylindrical or slightly inflated, 11-16 //. 

 diam., 3-8 diam. long, occasionally as much as 15 diam. ; 

 shorter above, in the upper branches about as long as broad ; 

 ramuli 6-8 /u. diam. at base. Mass., R. I., Conn. Europe. 



3. S. FLAGELLIFERUM Kiitzing, 1845, p. 198; 1853, PL X, 

 fig. i ; Wolle, 1887, p. 112, PI. XCVII, fig. i ; P. B.-A., No. 

 408 ; Myxonema flagelliferum Hazen, 1902, p. 199. Tufts up to 

 2 cm. long, bright green ; branches mostly in pairs, 2-4 pairs on 

 successive globose cells ; ramuli flagelliform, tapering into long 

 setae ; lower cells 14-18 ^ diam., 4-8 diam. long, C3 7 lindrical or 

 slightly inflated ; ramuli 9-10 /u diam. at base. Mass., Conn. 



Europe. 



This and the preceding species have much in common, but 

 ,5". flagelliferum is larger, with more elongate and tapering 

 branches, and more abundant and better developed setae. 



4. S. SUBULIGERUM Kiitzing, 1849, p. 354; Myxonema stibu- 

 ligerum Hazen, 1902, p. 200, PI. XXX. Tufted, less than i 

 cm. long ; much branched after the type of S. lubriaim, but 

 branches spreading, ramuli divaricate, tapering from the rather 

 thick base to an acute point, or occasionally into a short seta ; 

 cells cylindrical, about as long as broad, quite covered by the 

 dense chrornatophore ; main branches 12-16 ^ diam.; ramuli 

 6-9 /j. diam. at base. N. Y., N. J., Cal. Europe. 



Distinguished by the nearly uniformly opposite, divaricate 

 branching, thorn-like ramuli, and dense chrornatophores. 



5. S. ventricosum (Hazen) nov. comb.; Myxonema vcnfri- 

 cosuuj Hazen, 1902, p. 201, PI. XXXI. Tufted, up to i cm. 

 long ; main branches as in .S*. lubricum ; ramuli alternate or 

 opposite, short, tapering to the rounded tip or into a short, 

 rather obtuse seta; lower cells much inflated, 14-16 /u. diam. at 

 the ends, 27-30 /u. at the middle, length 45-110 /t; ramuli 6-8 ft 

 diam. at the base ; chrornatophore a narrow zone in the large, 

 inflated cells, occupying the greater part of the smaller cells. 

 N. J. 



The strongly inflated cells, with comparatively narrow zonate 



