64 MIXNKSOTA BOTANICAL STUDIES. 



short sterigmata ; basidiospores broadly elliptical or pear-shaped, 

 smooth, granulose, 6-10x4-8 mic. 



On stipe and frond of coarse mosses as Hypnum species; Eng- 

 land, Kings Cliffe (Cooke), Bear Island "(Saccardo) ; Minnesota 

 (Nelson). 



Explanation ok Plates. 



Plate XI. 



Exobasidiuni mycetophilum (Peck) Burt, natural size. 



Plate XII. 



Cantharelkis retirugus (Bull.) Fries, natural size. 



Figure i. Photographed in nature. 



Figure 2. Upper surface, single specimen. 



Figure 3. Lower surface, single specimen. 

 Plate XIII. 



F'igures 1-9. Exobasidium mycetophilum, magnified 485 dm. 



Figure i. Diagram of cross section of cap of host and para- 

 .; site. 



H = hymenium, S = sterile tissue of parasite, A = host. 



Figure 2. Old basidia. 



Figure 3. Clump of basidia tips. 



Figure 4. Isolated spores. 



Figure 5. Diagram of cross section of stipe of host and para- 

 site. 



H = hymenium, S = sterile tissue of parasite, A = host, C = 

 cavity of parasite. 



Figure 6. Basidia with spores. 



Figure 7. Young basidia tip with spores. 



Figure 8. Old basidia tip with sterigmata. 



F'igure 9. Clamp connections. 



Figures 10-16. Cantharelkis retirugus (Bull.) Fries. 



Figure 10, ii. Clamp connections. 



Figure 12. Old basidia. 



Figure 13. Young basidia Avith two spores. 



Figure 14. Basidia with four spores. 



Figure 15. Basidia with spores. 



Figure 16. Spores with sterigmata still attached. 



