EXPLANATIONS AND REFERENCES, 

 PLATE CLIV. 



Figures magnified 500 diameters. 



PAC4E. 



Figs. 1, 2. CHLAMYDOCOCCTJS NIVALIS, simple cells, . . . 160 



' 3,4. Cells dividing into two and into four parts, . . 166 



" 5, 6. CHLAMYDOMONAS TINGENS, a variety of sizes of macrogonidia, 167 



' 7, 8. CHLAMYDOMONAS PLUVIALE, the normal appearance, . 167 

 " 9, 10. OHLAMYDOMONAS HYALJNA, . . . . .168 

 Fig. 11-14. HYDRODICTYON UTBICULATUM, parts of coenobia of various 



degrees of development, . 170 



Figs. 15, 16. First stages of development, ..... 170 

 Fig. 17. Cell with microgonidia, in part escaping through a rupture of 



the membrane, highly magnified, . . . 170 



" 18. Part of cell with macrogonidia, highly magnified, . . 170 



19. Free macrogonidia, more highly magnified. . . . 170 



" 20. Zoospores or macrozoogonidia, ..... 170 



