253 



the original descriptions as given by Ellis and Everhart in "North Ameri- 

 can Pyrenomycetes", and Saccardo's "Sylloge Fungorum." Practically all 

 of the descriptions have been rewritten and additional data added from 

 specimens at hand. All measurements are original. Where asci and 

 spore measurements by Ellis and Everhart differ, their figures are also 

 given. 



KEY TO SPECIES. 



(Based on external characteristics.) 



I. Peritbecia large (f-PJ mm.), seated on a subiculum. 

 A. Subiculum usually prominent. 



1. Brown or purplish brown, persistent 1. R. aquila 



2. Sulphur-yellow, evanescent 6. R. subiculata 



B. Subiculum scanty. 



1. Dark brown, peritbecia crowded 2. R. medullaris 



2. Black, perithecia confluent 3. R. mammiformis 



C. Subiculum wanting, perithecia more or less scattered. 



1. Base glandular-roughened 4. R. glandiformis 



2. Not glandular-roughened 5. R. mutatis 



II. Perithecia small ($-i mm). 



A. Perithecia gregarious, often crustaceous, not bristly. 7 R. pulveracece 



B. Perithecia usually scattered, bristly, dark brown.... S. R. Ugniaria 



(Based largely on microscopic characteristics.) 

 A. Perithecia large (f-li mm). 



B. Spores more tban 18 microns long. 



C. Asci more than 150 microns long 1. R. aquila 



OC. Asci less than 150 microns. 



D. Asci 7-8 microns wide 2 R. medullaris 



DD. Asci 8-10 microns wide 3. R. mammiformis 



BB. Spores less than 18 microns long. 



C. Asci more than 95 microns long 4. R. glandiformis 



CC. Asci less than 95 microns. 



D. Perithecia jr! mm 5. R. mutans 



DD. Perithecia 3-1 mm 6. R. subiculata 



A A. Peritbecia small (^-J mm). 



B. Asci more than 70 microns long 7. R. pulveracew 



BB. Asci less than 70 microns long 8. R. Ugniaria 



