CEDOGONIUM. 89 



OEDOGONIUM PACHYANDRIUM, Wittr. 



Oogonia single or twin, moderately swollen, obovate- ellip- 

 soid, opening by a pore above the middle ; oospore ellipsoid 

 nearly filling the oogonium ; male plant slightly thicker than 

 the female ; spermogonia 1-4 celled ; spermatozoids binate. 



Diameter veg. cells, 31-36 yw; 2^-62 times longer. 

 Diameter oogon. , 54-57 yu by 90-108 yw. 

 Diameter oospor., 51-54 ju by 73-85 yw. 

 Diameter sperm, cells, 35-43 yu by 11-20 yw. 



Stagnant waters, railroad ditches, Pennsylvania, New 

 Jersey, frequent. 



Plate LXXV, fig. 9, female, and fig. 10, male plant. 



OEDOGONIUM RUFESCENS, Wittr. 



Oogonia single or 2-3 seriate, globose or obovate globose, 

 opening by a pore in the middle ; oospore globose filling the 

 oogonium ; male and female plants of same size ; spermogonia 

 6-12 celled. 



Diameter veg. cells, 8-10 yw ; 5-6 times longer. 

 Diameter oogon., 22-24 yw tiy 24-30 yw. 

 Diameter oospor. , 21-23 yw by 20-22 //. 

 Diameter sperm, cells, 6-8 yw by $-12 yw. 



Plate LXXXI, figs. 16, 17, male and female plants. 



OEDOGONIUM FRANKLINIANUM, Wittr. 



Dioecious, macrandrous; oogonia single or rarely twin, 

 subglobose, opening by a pore above the middle ; oospore 

 globose filling the oogonium, membrane firm ; filaments of 

 male plant slightly smaller than the female. 



Diameter veg. cells, fern., 9-12 /^ 3-6 times longer. 

 Diameter veg. cells, mas. , 8-9 yu ; 3-5 times longer. 

 Diameter oogon. , 26-31 yw by 29-41 /*. 

 Diameter oospor., 25-29 ^ by 24-30 yw. 

 Diameter sperm, cells, 8-9 yu by 5-7 yw. 



This species from pond, Franklin, New Jersey, stands 

 between Oe. rufescens, Wittr., and Oe. Ltundellli, Wittr. 



Plate LXXXII, figs. 7, 8, two female plants ; fig. 9, male 

 plant. V. specimens, Wittrock and Nordstedt's Algse 

 Exsiccatse, No. 309. 



