580 EPHEMERIN.E. 



25. CLOEON DIMIDIATA. 



Castaneo-fusca ; prothoracis lateribus puncto ochraceo , pedibus 

 stramineis. 



Cloe dimidiata, Pictet, Hist. Nat. Neur. Eph. 272. 

 Cloeon dimidiatum, Curt. Phil. Mag. 1834, 121. Steph. ILL Brit. 

 Ent. Hand. vi. 69, 7. 



England. 



26. CLOEON VIRGO. 



Pallida ; oculis nigris ; femoribus anticis apicem versus obscuris ; 

 alis hyalinis. 



Cloeon virgo, Steph. III. Brit. Ent. Mand. vi. 70, 8. 

 Cloe ? virgo, Pictet, Hist. Nat. Neur. Eph. 272. 

 Ephemera virgo ? Oliv. Latr. Hist. Nat. Ins. xiii. 98. 



England. 



Genus 6. C-ENIS. 



Oculi remoti, maris simplices. Pedes bene determinati. Alae 

 dua3, venis transversis paucis. 



Caenis, Stephens; Pictet. 

 Ephemera, p., Fabr. 

 Brachvcercus, Curt. 

 Oxycypha, Burm. 

 Ephemerae trisetas, p., Zett. 

 Coenidae, Newman. 



Eyes simple in both sexes, and always separated by a broad in- 

 terval : wings two, much rounded on the internal border, fan- 

 shaped, almost without transverse veins: body short and broad: 

 ungues of the tarsi terminated by two small laminae ; three tail- 

 bristles of equal length, very long in the male, and very short in 

 the female. 



