[Vol. 2, 1915] 



728 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



Explanation of Plate 



PLATE 24 



Fig. 10. View of hymenium of P. spumcus. 



Fig. 11. The pores of P. spumcus somewhat enlarged. 



Fig. 12. Section through a sporophore of P. galactinus. Note the 



prominent zonation of the context. 



Fig. 13. Upper surface of P. chioneus. 



Fig. 14. Comparison of the size of the tubes in (a) P. spumcus and 



(b) P. dclcctans. 



Fig. 15. Upper surface of P. galactinus. Note the prominent 



pubescence. 



Fig. 10. Sections showing the relative thickness of the pilei in (a) 



P. albellus and (b) P. chioneus. 



Fig. 17. Hymenium of P. galactinus. 



