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



Diameter veg. cells, 15-16 yu; 1-11 times longer. 

 Diameter oogon. , 26-28 yu by 39-42 /x 

 Diameter androsp. cells, 11-12 yu by 12-16 p. 

 Diameter dwarf males, 10-11 /* by 15 yw. 

 Diameter sperm, cells, 7 // by 7 yw. 



Syn. jB. pygmaea var. major, Pringsh. ; _B. dumosa, Wood, is 

 probably a form of this species or of B. varians, Wittr. 

 Pennsylvania. 



Plate XC, fig. 5, a fertile plant. 



BULBOCHAETE REPANDA, Wittr. 



Oogonia somewhat oblong ellipsoid, patent or rarely erect, 

 beneath vegetative cells or terminal setae or androsporangia ; 

 aiidrosporangia epigynous; dwarf males on or near the 

 oogonia. 



Diameter veg. cells, 12-15 yw 2-3} times longer. 

 Diameter oogon. , 26-30 yw by 45-58 /^. 

 Diameter androsp. cells, 11-14 yw by 16-21 //. 

 Diameter dwarf males, 10-14 yw by 21-22 yw. 

 Diameter sperm, cells, 8-9 yw by 5-6 u. 



Lake Hopatcong, New Jersey. 

 Plate XC, fig. 4, a fnlly developed plant in fruit. 



BULBOCHAETE RECTANGULARIS, Wittr. 



Oogonia ellipsoidal, patent or rarely erect, beneath a term- 

 inal seta, or beneath an androsporangium cell, or a vegeta- 

 tive cell ; androsporangia scattered or epigynous ; vegetative 

 cells somewhat qnaiidraiigular in longitudinal sections ; 

 horizontal division of vegetative cells often occurs. Branches 

 few but often long ; dwarf males seated about or upon the 

 oogonia. 



Diameter veg. cells, 16-23 yw ; 11-2 times longer. 

 Diameter oogon. , 33-39 yu by 48-55 //. 

 Diameter androsp. cells, 15-16 yw by 16-27 yw. 

 Diameter dwarf males, 15-18 /u by 22-27 yw. 

 Diameter sperm, cells, 8-9 yu by 5-6} //. 



A species which varies considerably in size and in the 

 branching ; filaments often long, almost devoid of branches ; 

 the dwarf males often scattered and spermogonia cells some- 

 times separated by septae which project, rib-like, beyond 

 the walls of the spermogonia. B. ignota, Wood, is probably 

 a form of this species. 



Plate XC, figs. 1-3, two forms of this species. 



