84 FRESH-WATER ALG-JS OF THE UNITED STATES. 



Found it in tangled masses floating in a pool in Florida, 

 near Winter Park ; filaments a foot or more in length, almost 

 devoid of chlorophyl ; oospores and supporting cells vegeta- 

 tive green. 



Diameter veg. cells, 7-8 ^ 5-11 times longer. 

 Diameter oogon. , 33-35 j* by 45-50 yw. 



Plate LXXXV, figs. 1, 2. 



Var. BOREALE, Wolle. 



Is the form common in Pennsylvania and New Jersey ; it 

 is short, more robust, articulations only 3-5 diameters, 

 dwarf males short, with spermogonia one- celled. 



Diameter veg. cells, 14-16 // ; 3-5 times longer. 

 Plate LXXIX. figs. 10, 11. 



OEDOGONIUM OBTRUNCATUM, Wittr. 



Oogonium single or more rarely twin, broadly elliptic or 

 globose-ellipsoid, usually terminal, opens by an apical oper- 

 culum ; supporting cells the same as the vegetative cells. 

 Oospore filling the oogonium. 



Diameter veg. cells, 8-12 yw ; 2-4 times longer. 



Diameter oogon., 15-17 JJL by 17-20. 



Frequent in pools, parasitic on culms of water plants. Not 

 quite identical with the India form described by Wittrock, 

 but nearly related; may be considered a small form. 



Plate LXXIX, figs. 12, 13. 



OEDOGONIUM CILIATUM, ( Hass. ) Pringsh. 



Gynandrosporous; oogonia 2-7 seriate or single, oval, open- 

 ing by an operculuni ; oospore oval, nearly filling the oogo- 

 nium ; androsporaiigia 2-8 celled ; terminal cell setiform ; 

 dwarf males curved, seated on the oogonium ; sperinogoiiia 

 unicellular. 



Diameter veg. cells, 12-20 yw; 2 2 -5 times longer. 

 Diameter oogon., 40-45 j* by 52-70 yw. 

 Diameter oospor. , 38-44 yw by 45-55 yw. 

 Diameter dwarf males, 10-15 yu by 28-30 yw. 



Marsh pool, Atsion, Ne\v Jersey. Not quite the same as 

 the European form but near it. 



Syn. Vesiculifera ciliata, Hass ; Oe. piliferum, Auers. 

 Plate LXXXIV, fig. 10, a filament (fern.) in fruit. 



