PLATE CXXVI. 



FIGS. PAGE 



1-2. Staurastrum trachytithophorum W. &G.S.West. 



x 520. 2, zygospore . . . 165 



o.St. rugulosum ~Bre\). x 400 (after Ralfs.) . 178 

 4. #. botropliihim Wolle. x 520 . . 160 



5-6. $. turgescen* De Not. x 520 . . 167 



7. St. Donardmse W. & G-. S. West, x 520 . 169 

 8-9. St. alternant Breb. 8, a typical specimen, x 

 520; 9, x 400 (after the poor fierure given 



by Ralfs) . 170 



i/ / 



Fiar. 9 n is only the outline of the front 



O 



view ; both 9 a and 9 d are poor figures and 



scarcely represent the species. 

 10-15. 5*. dilatatum Ehrenb. 10, x 400 (after the 



very poor figure given by Kalfs) ; 1 1 and lo, 

 x 520; 12 "x 550; 14, "x 840; 15, supposed 



xygospore, x 400 (after Roy and Bissett) . 172 

 Fig. 10 a is only the outline of the front 



view, but neither Wa nor 10 d are very good. 



Figs. 11-14 are typical examples of St. 



dilatatum. 

 W.St. d't^mtatnni W. & G. 8. West. x about 540 



(after Raciborski). This figure is imperfect 



as the granulation is insufficiently depicted . 176 

 17. St. disputatum var. extensum (Borge) W. cS: G. S. 



West. x 740 (after Borge) . .177 



18. St. dilatatum var. hibemicum \\ . cN^ (T. S. 



West, x 520 . . 175 



19. St. disputatum var. */;/r?^-p (Liitkein.) W. tV 



(i. S. West. x 600 (after Lutkemuller) . 176 



