THE GREEN ALGAE OF NORTH AMERICA 247 



A widely distributed species, but the occurrence with us of 

 the typical form is recorded only by Wolle, who does not men- 

 tion var. Nordstcdtii, which certainly does occur here ; possibly 

 his plants belong rather to the variety. 



Var. NORDSTEDTII \Vittrock in Wittr. and Nordst., Alg. 

 Exsicc., Nos. 8 and 205; Him, 1900, p. 171, PI. XXVII, fig. 

 156. Smaller, oogonia single, rarely 2, oboviform-globose, 

 oospore not quite filling the oogoniutn. 



veg. cell, female, 10-16 M diam., 2-4}^ diam. long. 



veg. cell, male, 9-15 M " 2-4^ " 



oog., 28-39 fj. " 36-45 Mong. 



oos., 26-34 n " 27-34 M 



anth. cell, 9-12 /* " 8-9 n " 



Greenland, Minnesota, Cal. Europe, Asia. 



MACRANDRIA, OPERCULATA, ELLIPSOSPORA. 



39. OE. AHLSTRANDII Wittrock in Wittr. and Nordst., Alg-. 

 Exsicc., No. 401 ; Him, 1900, p. 183, PI. XXIX, fig. 179. 

 Monoecious; oogonia ellipsoid, single, operculate, division su- 

 perior ; oospore ellipsoid, filling the oogonium, membrane 

 smooth; antheridium i-2-celled, hypogynous ; spermatozoids 

 binate, division horizontal : terminal cell obtuse. 



veg. cell, 10-18 M diain., 3-10. diam. long, 



oog., 34-42 M " 57- 6 9 M long. 



COS., 34-41 M " 53-62 fJ. " 



anth. cell, 13-17 M " 9' 12 /" " 



N. Y. Sweden. 



40. OE. GRACiivLiMUM Wittrock and Lund in Wittrock, 

 1874, p. 15 ; Wolle, 1887, p. 74, PI. LXXV, fig. 2 ; Him, 1900, 

 p. 184, PI. XXIX, fig. 180. Monoecious; oogonia single, 

 oblong, operculate, division superior ; oospore oblong-ellipsoid, 

 not filling the oogonium, membrane smooth ; antheridia subepi- 

 gynous, hypogynous or subhypogynous, unicellular ; spermato- 

 zoids binate, division horizontal. 



veg. cell, 3^-7 ^diam., 4^-6 diam. long, 



oog., 14-19 M " 34-40 /j. long, 



oos., 13-17 /" " 24-32^ " 



anth. cell, 3-5 M " 4'7 /* " 



Pa. Europe. 



41. OE. NODULOSUM Wittrock, 1872, p. 22, PL I, figs. 8-10 ; 

 Him, 1900, p. 187, PI. XXIX, fig. 184. Monoecious; oogonia 

 single or 2, oboviform-globose, more rarely oboviform-ellipsoid, 

 operculate, division superior ; oospore globose or subglobose, 

 more rarely globose-ellipsoid, almost filling the oogonium, mem- 



