EXPLANATION OF PLATES 



All of the I ha wings except figure 30 of plate 41 were made by Dr. Helen M. 

 Gilkey under the direction of the writer. Figure 30 of plate 41 was drawn by 

 Mr. H. N. Bagley under the direction of Professor W. A. Setchell. 



PLATE 38 

 Placoma violacea Setchell and Gardner 

 Fig. 1. Habit sketch of the thallus. 



Fig. 2. Perpendicular section through young confluent thallus showing the 

 more or less radial arrangement of the cells. 

 Fig. 3. Surface view of a group of cells. 



Dermocarpa protea Setchell and Gardner 

 Fig. 4. A series of gonidangia illustrating different shapes and sizes. X 250. 

 Fig. 5. A group of cells showing various stages of gonidial formation. 

 X 250. 



Anacystis eldbens (Kuetz.) Setchell and Gardner 

 Fig. 6. Surface view of a colony, showing tendency to break up into 

 groups of cells. X 125. 



Fig. 7. A single group of cells from the colony. X 500. 



Xenococcus Cladophorae (Tilden) Setchell and Gardner 

 Fig. 8. A group of vegetative cells in various stages of growth and inter- 

 spersed gonidangia. X 250. 



PJeurocapsa eniophysaloides Setchell and Gardner 

 Fig. 9a-g. A series of vegetative cells in various stages of development. 



h'i, two gonidangia. X 250. 



Fig. 10. Section view through a large colony showing the somewhat en- 



tophysaloid arrangement of groups of cells. X 250. 



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