1931 ] 
Notes on the Genus Ephemerella 
29 
Fig. 1. 
1. E. septentrionalis — wings of adult; 
2. E. cornuta — wings of adult; 
3„ E . septentrionalis — head of nymph; 
4. E. septentrionalis — hypopharynx ; 
5. E. septentrionalis — maxilla ; 
6. E. cornuta — forceps and penes of adult; 
7. E. rotunda — forcep and penis of adult; 
8. E. septentrionalis — forcep and penis of adult. 
