558 EPHEMERIN^. 



8. BAETIS SEMITINCTA. 



Femora anteriora fulva ; alee dimidio basali mediocriter color ata, 

 areola costali immaculata. 



Baetis semitincta, Pictet, Hist. Nat. Neur. Eph. 180, 8, pi. 22, 

 f. 13. 



Switzerland. 



9. BAETIS OBSCURA. 

 Corpus omnino nigrum ; alee hyalince ; areola coslalis invaria. 



Baetis obscura, Steph. III. Brit. Ent. Mand. vi. 65, 9. Pictet, 

 Hist. Nat. Neur. Eph. 182, 9, pi. 23, f. 1. 



a ? England. Presented by F. Walker, Esq. 



10. BAETIS CEEEA. 



Corpus omnino fulvum vel flavum ; alee hyalince aut basisubtinctce, 

 areola costali immaculata, venis transversis fulvis indistinctis . 



Baetis cerea, Pictet, Hist. Nat. Neur. Eph. 183, 10, pi. 23, f. 2. 



a. England. Presented by F. Walker, Esq. 



b. England 



11. BAETIS SULPHUBEA. 



Corpus latum, stramineum ; oculi virides ; alee hyalines aut basi 

 subtinctce, areola costali basi hyalina apice colorata. 



Baetis sulphurea, Pictet, Hist. Nat. Neur. Eph. 185, 11, pi. 23, f. 3. 

 Ephemera sulphurea, Mutter * Zool. Dan. Prodr. 142, 1645. 

 Ephemera helvola ? Sulz. Abg. Gesch. pi. 24, f. 7. Roemer, Gen. 



pi. 24. 

 Baetis straminea ? Curt. Phil. May. 1834, 121. 



Europe. 



