98 FRESH-WATER ALG^ OF THE UNITED STATES. 



BULBOCHAETE POLYANDRA, 



Idio-androsporous ; oogonia somewhat depressedly globose, 

 seated beneath a terminal seta or a vegetative cell ; dissepi- 

 ment of supporting cell usually much above the middle ; 

 epispore delicately crenulate or nearly smooth ; audrospor- 

 angia 4-10 celled ; dwarf males seated on the oogonia, stem 

 curved. 



Diameter veg. cells, 15-20 }JL ; 3-6 times longer. 

 Diameter oogon. , 36-46 ju by 32-38 yw. 

 Diameter androsp. cells, 13-14 // by 12-15 yw. 

 Diameter dwarf males, 8-9 /* by 20-23 //. 



Culms, margins of lakes, Florida, often full of this species; 

 did not identify it farther north. 



Plate LXXXIX, figs. 6, 7, female and male plants ; 8, 9, 

 the androsp orangia. 



BULBOCHAETE SETIGERA, (Roth.) Ag. 



Oogonium depressedly subquadrangularly globose, seated 

 beneath a terminal seta, or beneath an androsporangium ; 

 membrane of the oogonium thickened after fertilization, 

 dissepiment of the supporting cell a little above the middle 

 or at the middle; epispore granulated; androsp or angi a 

 scattered or epigynous, bicellular ; dwarf males seated upon 

 or about the oogonia, stems straight. 



Diameter veg. cells, 25-28 // ; 2i-5 times longer. 

 Diameter androsp., 18-20 /* by 14-18 yw. 

 Diameter oogon. , 75-80 ^ by 60-65 //. 

 Diameter dwarf males, 12-14 /* by 34-36 yw. 



Syn. B. Canbyii, Wood. 



Cannot find sufficient distinction in this form described in 

 Wood's Contribution, p. 202, to separate it from the 

 European B. setigem. It bears also a resemblance to B. 

 iliSj Wittr. 



Not infrequent in New Jersey, Florida, South Carolina. 

 A peculiar form probably of this species found in quantity 

 fringing willow rootlets, sticks and the like in pond, at 

 Hammonton, New Jersey, August, 1879. It was destitute of 

 fruit ; no oogonia, instead the plants were numerously fur- 

 nished with distinct, sessile, oval, pod-like cells dehiscing 

 at the top, making a lid (operculum) which opens, and soon 

 a zoospore escapes. 



