SMITH: TETRADESMUS, A NEW COENOBIC ALGA 87 
Fic. 4,5. Transverse sections of colonies. 
- 6. Various forms taken by the pyrenoid and the surrounding starch layer 
Fic. 7. Cell showing ‘‘stroma” starch granules. 
F - Cell showing the pyrenoid with segmented starch ring. 
Fic. 9. A cell after the first nuclear division. 
Fic. 10A, 10B. Completion of first cell division. 
Fic. 11. After the completion of the second nuclear division. 
- 12-14. Stages in the second cleavage of the cytoplas 
IG. I5, 5A. Beginning of elongation of the four daughter ‘tlle 
Young colony inside of mother cell wall (lateral view). 
IG. I7. Young colony, immediately after liberation from mother cell. 
Empty mother cell walls after liberation of young colonies. 
End view of daughter colony, showing method of its liberation from 
mother cell walk 
Fic. Transverse section of coenobe, showing young colony within the wall 
of one of the mother cells. 
