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



veg. cell, female, 14-23 M diam., 3-6 diam. long. 



veg. cell, male, 13-18 M " 4-6 " 



oog., 39-51 M " 75-110 M long. 



oos., 36-43 M " 56-70 M " 



anth. cell, 13-14 M " 6-16 M " 



Greenland, Mass., Conn., Cal. Europe, So. America. 



Forma DISPAR Him, 1900, p. 124, PI. XIV, fig. 76 ; P. B.-A., 

 No. 1226. Oospore smaller, ellipsoid-globose or sub-globose; 

 oogonia shorter, sometimes suboviform. 



veg. cell, 14-21 ,u diam., 4-7 diam. long. 



oog., 38-45 /j. " 70-92 M long. 



oos., 34-43 M " 44-55 fj. " 

 Mass., Pa., Cal. 



Var. OCCIDENTALS Him, 1900, p. 125, PI. XIV, fig. 77. 

 More slender in all parts, vegetative cells longer ; male plant 

 same diameter as the female. 



veg. cell, female, 8-15 M diam., 6-n diam. long. 



veg. cell, male, 8-15 M " 6-u " " 



oog., 33-38 fj. " 75-100 fj. long. 



oos., 32-37 fj. " 45-50 fj. " 



anth. cell, 12-13 n " 10-16 M " 



Kittery, Maine. 



22. OE. MARGARITIFERUM Nordstedt and Him in Him, 

 1900, p. 128, PI. XV, fig. 83. Dioecious; oogonia single, sub- 

 oblong or suboviform-ellipsoid or subellipsoid, pore superior; 

 oospore ellipsoid or globose-ellipsoid, not nearly filling the 

 oogonium, or rarely nearly filling it ; membrane triple, with 

 longitudinal lines on the inner surface of the outer membrane 

 and the outer surface of the median membrane ; lines 30-35, 

 sometimes anastomosing, not continuous, but made up of some- 

 what elongate dots ; male plant somewhat more slender than 

 the female ; antheridia to lo-celled ; spermatozoids binate, divi- 

 sion vertical. 



veg. cell, female, 23-28 /u diam., 3/4-7 diam. long. 



veg. cell, male, 17-23 fj. " 4^-7 " " 



oog., 50-63 M " 82-100 M long. 



oos., 48-61 fj. " 55-75 M " 



auth. cell, 18-20 M " 7-13 ^ " 



So. America. 



Hirn considers as probably belonging to this species the plant 

 figured by Wood, 1872, PI. XVIII, fig. 4, but not named, and 

 on this probability it is here included. It varies considerably 

 in the size and shape of the oogonium and oospore, but on care- 



