PLATE CLIV. 



FIGS. PAGE 



1-4. Staurastrum controversum Breb. 1, 2, and 3, x 520 

 (36 original) ; 4, zygospore, X 600 (after Liitke- 

 miiller) . . . .162 



5-7. St. cosmospinoxum Borg. 5, X 400 (after Roy & 

 Biss.) ; 6, X 390 (after Borgeson) ; 7, X ? (after 

 Borgeson) . . . .164 



8*. St. monticulosum Breb. X 510 . . 183 



9. St. monticulosum var. bifarium Nordst. Forma X 



520 . . . . . 184 



10. St. monticulosum var. grcenlandicum Gronblad. 



400 .... 185 



11. St. monticulosum Breb. ? ? X 520 (see p. 184) . 183 

 12.- St. monticulosum var. pulchrum West. X 520 (see 



p. 186) . . . .185 



13. St. megalonotum Nordst. X 570 (after Nordstedt) 182 

 14-16. S*. fotjictilatttm Lund. 14, x 520 ; 15*, X 510 ; 



16*, biradiate form, X 510. . . 187 



