BULBOCHAETE. 97 



SECTION I. OOGONIA GLOBOSE OR SUBGLOBOSE. 



A. Dwarf males unicellular. 



BULBOCHAETE ELACHISTANDRA, Wittr. 



Oogonia globose, beneath the androsporangia; dissepi- 

 ment of the supporting cell about the middle ; epispore 

 smooth ; androsporangia above the oogonia, or scattered ; 

 dwarf males very small, obovate, extending downward to a 

 thin point, nearly straight, seated on, or near the oogonia. 



Diameter veg. cells, 15-20 yu; H- 2i- times longer. 



Diameter androsp., 12-14 yu by 10-12 yu. 



Diameter oogon. , 40-45 yu by 40-45 //. 



Plate LXXXYI, fig. 5. 



B. Dwarf males Hcellular. 

 a. Basal part (stem or stipe} shorter than the spermogonia cells. 



BULBOCHAETE INTERMEDIA, D.By. 



Oogonia snbdepressedly globose, seated under the andro- 

 sporangia ; dissepiment of the supporting cell in the middle ; 

 epispore delicately crenulate (rarely smooth); androspor- 

 angia 1-2 celled, epigynous, rarely scattered ; dwarf males 

 seated on the oogonia, stems slightly curved. 



Diameter veg. cells, 16-19 yw ; I* -3 times longer. 



Diameter androsp., 13 yu by 10 yw. 



Diameter oogon., 40-48 yu by 31-40 /x 



Diameter dwarf males, 9-10 yw by 24-30 yw. 



( 'ommon in ponds and sluggish waters ; varies considerably 

 in diameter of filaments, length of cells, etc. 



Plate LXXXVI, figs. 1, 2, 3, three forms. 

 BULBOCHAETE CEENULATA, Pringsh. 



* 7 O 



Oogonia depressedly globose, seated beneath terminal 

 setae, rarely beneath androsporangia or vegetative cells. 

 Dissepiment of supporting cell in the middle or slightly 

 below it; epispore distinctly crenulate; androsporangia 

 scattered, rarely epigynous ; dwarf males seated on or near 

 the oogonia, stems nearly straight. 



Diameter veg. cells, 16-19 yw; 2-3^ times longer. 



Diameter androsp., 12 yw by 10 yw. 



Diameter oogon. , 45-48 yu by 35-38 yw. 



Diameter dwarf males, 9 yu by 26 yw. 



Pennsylvania, New Jersey and probably in every State. 



Plate LXXXVI, fig. 4. 



