PLATE XLIII. 



Figures magnified .500 diameters, except the Micrasl-erias and Closteriums only 

 about one-half. 



Page. 

 Fig. 1. MiCRASTEEIAS EADIOSA, Ralfs, Var. PUNCTATA, West, . 119 



Figs. 2, 3. Xanthidium antii-opaeum. Kg., .... 101 



Var. Canadense, Joshua, front 



and end views, . 102 



Fig. 4. CosMARiUM Regnbsi, Eeinsch, . . 70 



Figs. 5, 6. Staubastbum angitlatum. West, . . 132 



" 7, 8. Sphaerozosma serratum, Bailey ; two varieties from Florida, 30 



" 9, it), SpHAEB'izosMA (Onychonema), Nobdstedtiana, Turner, 31 



" 11-13. CoSMARiuM Meneghinii, Breb., forma octangularis, Wille, 



Var. simplicissimum, Wille, 70 



Fig. 14. CosMARiuM l/AEVE, Rab., Var Septemtrionale, Wille, . 72a 



" 15. GoNATOZYGON SEX-spiNiTERUM, Turner, . . 172 



" 16. Calocylejdrtjs Cucdebita ( Breb.), Kirch., . . 59 



Figs. 17, 18. CoSMABruM (Calocylindrus) Cordanum, Breb., 59 



Fig. 19. Closterium Beaunii, Reinsch, . . 45 



" 20. Closterium subdieectum, West, . . . .46 



" 21. Closterium eostbatum, Ehrb., . . . 49 



Var. brevirostratum, West , . 49 



" 22. CLOSTERruM Leibleinh, Kg., .... 49 



Var. curtum West, . . .49 



