PLATE CLVI. 



FIGS. PAGE 



l.Staurastrum diplacanthum De Not. X about 600 



(after de Notaris) . . . 186 



2. St. diplacanthum var. anglicum Turn. X about 450 



(after Turner) . . . 186 . 



3. St. senarium (Ehr.) Ealfs. X 513 . 171 



4. . Westii Turn. about 400 (after Turner) . 187 

 5. St. gemelliparum Nordst. X 520 . .176 



6 St. Clevei (Wittr.) Roy & Biss. x 520. . 177 



7-8. St. furcigerum T&ieb. 7*, X 510; 8, zygospore, X 



520 . . . . .188 



9. St. furcigerum var. reductum \V. & GL S. W. X 520 192 

 10. St. furcigerum forma armigem (Breb.) Nordst. 



( 520 . . . . . 191 



1 J . St. furcigerum forma, x 520 . .188 



