EPHEMERIN^E. 545 



Potamanthus gibbus, Pictet, Hist. Nat. Neur. Eph. 226, 9, pi. 



31, 32. 

 Switzerland. 



17. POTAMANTHUS SUBMABGINATUS. 



Rufo-piceus ; pedibus pallidioribus, geniculis posticis nigricanti- 

 bus ; alls hyalinis, costa subochracea. 



Ephemera submarginata, Steph. III. Brit. Ent. Mand. vi. 58, 7. 

 Potamanthus submarginatus, Pictet, Hist. Nat. Neur. Eph. 236. 



Allied to P. erythrophthalmus. 

 England. 



18. POTAMANTHUS DILUTUS. 



Pallide rufo-ferrugineus ; abdomine nigricante ; pedibus pallidis ; 

 alis hyalinis costa concolore. 



Ephemera diluta, Steph. III. Brit. Ent. Mand. vi. 58, 10. 

 Potamanthus dilutus, Pictet, Hist. Nat. Neur. Eph. 236. 



England. 



19. POTAMANTHUS EOSEUS. 



Pallide roseus, subnitidus; pedibus pallidioribus; setis luridis fusco 

 maculatis ; alis hyalinis basi summa et costa dilute roseis. 



Ephemera rosea, Steph. III. Brit. Ent. Mand. vi. 59, 13. 

 Potamanthus voseus, Pictet, Hist. Nat. Neur. Eph. 236. 



England. 



20. POTAMANTHUS ^ENEUS. 



Corpus latum, breve, Icete coloratum ; mesothorax maris saltern non 

 lineatus ; abdomen fere unicolor ; alee indistincte reticulatce, 

 regione subcostali vix colorata, vena subcostali omnino fiava. 



Potamanthus aeneus, Pictet, Hist. Nat. Neur. Eph. 229, 10, pi. 33. 

 Switzerland. 



