268 TUFTS COLLEGE STUDIES, VOL. II, No. 3 



ii. Vegetative cells about as loug as broad, moniliform. 



ii. 

 ii. Vegetative cells longer than broad, subcylindrical. 12. 



12. Oogonium 20-25 M diam. 12. B. nana. 



12. Oogonium 26-35 M diam. 13. B. mirabilis. 



13. Suffultory cell without dissepiment. 14. B.pygmaea. 



13. Suffultory cell with dissepiment. 14- 



14. Oogonium about i^ times as long as broad. 15. 



14. Oogonium about 1^4 times as long as broad or more. 



19. B. minor. 



15. Oogonium 26-39 M diam. 16. 



15. Oogonium 44-60 /JL diam. 18. B. insignis. 



16. Vegetative cells repand. 17. B. rcpanda. 



16. Vegetative cells cylindrical. 17- 



17. Cells rectangular in longitudinal section. 16. B. redangularis. 

 17. Cells oval or subtriangular in longitudinal section. 



15. B. varians f. snbsiniple.r. 



18. Dwarf males shorter than the oogonium. 9. B. crassinscula. 



18. Dwarf males longer than the oogonium. 10. B. gi-gantea. 



GLOBOSPORAE. 



1. B. BREBISSONII Kiitzing, 1855, p. 19, PL LXXXVI.B ; 

 Him, 1900, p. 323, PI. 1,1, fig. 330; Rabenhorst, Algen, No. 

 1055. Dioecious, nannandrous, gynandrosporous ; oogoiiia 

 depressed-subquadrangular-globose, erect, below terminal setae 

 or androsporangia ; dissepiment of suffultory cell very low ; 

 epispore of oospore scrobiculate ; androsporangia scattered or 

 epigyuous, i-3-celled ; dwarf males on oogonia, more rarely near 

 them, antheridium interior, stipe slightly curved, shorter than 

 the antheridium. 



veg. cell, 17-20 /u. diam., 3-4/^ diam. long. 



oog., 42-50 fj. " 37-45 Mlong. 



andr. cell, 11-15 M " 12-18 M " 



nan., 10-12 //. " 28-33 ^ " 



Mass., Alaska. Northern Europe. 



The only species with interior antheridium and erect oogonia. 



2. B. INTERMEDIA De Bary, 1854, p. 72, PI. IV, figs. 1-7; 

 Wolle, 1887, p. 97, PI. LXXXVI, figs. 1-3 ; Him, 1900, p. 

 326, PI. 1,11, fig. 333; P. B.-A., No. 973. Dioecious, nannan- 

 drous, gynandrosporous ; oogonia sub-depressed-globose, pat- 

 ent, below the androsporangia ; dissepiment of suffultory cells 

 about median ; epispore of oospore pitted or more rarely smooth- 

 ish ; androsporangia i-, rarely 2-celled, epigynous, more rarely 

 scattered ; dwarf males on oogonium ; antheridium interior, 

 stipe slightly curved, shorter than the antheridium. Fig. 82. 



