88 FRESH-WATER ALG^E OF THE UNITED STATES. 



Syn. Conferva capiUaris, Linn ; Oe. regular e, Vaup. 



One of our most common forms, at the same time one 

 rarest in fruit. Variable in size from 25-50 yw in diameter j 

 filaments often a yard or more in length. 



Plate LXXXIII, figs. 7, 8, female and male plant. 



OEDOGONIUM STAGNALE, Kg. 



Oogonium single, slightly tumid, subcylindrical, opens by 

 a pore above the middle ; oospore subcylindrical or globose- 

 ellipsoidal, sometimes slightly constricted in the middle, 

 nearly filling the oogonium ; masculine plant slightly less 

 in diameter than the female ; spermogonia 1-3 celled, alter- 

 nating with vegetative cells. 



Diameter veg. cells, 42-46 yw ; 1J-2 times longer. 

 Diameter oogon., 49-50 yw by 65-75 yw. 

 Diameter oospor. , 47-49 yu by 50-66 yw. 

 Diameter sperm, cells, 36-38 yu by 7-9 yw. 



Very near Oe. capillare, barely separable except by the 

 somewhat swollen oogonia. 



Plate LXXXIII, figs. 3, 4, two filaments of female plant ; 

 fig. 5, male plant ; fig. 6, a cell in a neutral plant, the chloro- 

 phylous contents broken up into small spherical motile 

 cells (gonidia) which are passing out by an aperture in the 

 side. 



d. Oogonia manifestly swollen. 

 1. Oospor es globose or subglobose. 



OEDOGONITJM CAPILLIFORME, Kg. 



Oogonia single, obversely egg-shaped, opens by a pore 

 above the middle ; oospore subellipsoid, globose or cylin- 

 drical-globose, not filling the oogonium ; male plant slightly 

 smaller than female"; spermogonia 2-10 celled; terminal cell 

 obtuse. 



Diameter veg. cells, 32-38 yu ; li-3 times longer. 

 Diameter oogon., 42-48 yu by 51-62 yw. 

 Diameter oospor. 37-45 yw by 40-50 yw. 

 Diameter sperm, cells, 20-25 yw by 8-10 yw. 



Stagnant waters. 



Plate LXXV, figs. 11, 13, filaments of female plants ; fig. 

 12, male plant with spermogonia cells. 



