EXPLANATIONS AND REFERENCES, 



PLATE CLI. 



Figures magnified from 100-400 diameters. 



PAGE. 

 Fig. 1-4. VOLVOX GLOBATOR, different stages of growth under low 



magnification ; the latter with encysted 

 resting spores, .... 158 



" 5. Part of a coenobium of Sphaerosira volvox, Willn. Merely a 



condition of Volvox globator, .... 159 



" 6. Protoplasmic mass from the same under high magnification, 1 59 



Figs. 7, 8. The mass dividing into two, and four parts, . . . 159 



Fig. 9. Dividing into thirty-two parts each with cilia, shown in lateral 



view, ....... 159 



" . 10. A discoid family revolving in the mother sphere or apart from 



i 



it, but in close proximity, . . . . .159 



" 1.1. STEPHANOSPHAERA PLUVIALIS, a globose, vertical view, . 163 



" 12. Lateral view with fusiform primordial cells, . . . 163 



" 13. Formation of macrogonidia, . . . . .163 



" 14. Division of macrogonidia, ..... 163 



" 15. GONIUM PECTORAL.E ; lateral view of coenobium, . . 163 



Figs. 16, 17. Two coenobia in front view, ..... 163 



Fig. 18. A coenobium before division, . . . . .163 



