PLATE XXXVII. 



FIGS. PAGE 



1. Euastrum pingue Elfv. x 520 . . 30 



2-5. #. insigne Hass. 2, x 430 ; 3-5, x 520. Fig. 5 

 is a stouter form than fig. 2, but all inter- 

 mediate forms exist . . .31 

 6. E. intermedium Cleve. x 520 . .33 

 7. E. Webbianum Turn, (forma major Turn.). 



x 400 (after Turner) . . .34 



8. E. Sendtnerianum Reinsch. x 1200 approx. 



(after Beinsch) . . .34 



9-10. E. TurneriiWest, 9, x 400; 10, x 430 . 37 



11-13. E. rostratum Ralfs. 11, x 400 (after Ralfs) ; 



12 and 13, x 520 . . .35 



14-15. E. spinosum Ralfs. 14, x 400 (after Ralfs) ; 



15 x 520 . . . 38 



16-19.^. Udentatum Nag. 16-18, x 430; 19, zygo- 



spore, x 520 . . . .39 



