558 EPHEMERIN.E. 



8. Baetis SEMITINCTA. 



Femora anteriora fulva ; alee dimidio basali mediocriter colorata, 

 areola costali immaculata. 



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

 f. 1—3. 



Switzerland. 



9. Baetis obscura. 

 Corpus omnino nigrum ; aim hyalines ; areola costalis 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 cerea. 



Corpus omnino fulvum velfiavum ; alee hyalines aut basi sub tine tee, 

 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 sulphurea. 



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, Midler, 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. 



