EEV. A. E. EATON ON EECEXT EPHE.MEKID.E OR MAYFLIES. 313 



A nameless insect differs from Campsiirus in 



having an abundance of cross-veinlets Plate VI. 8 bis. 



„ .... The aforesaid interspace contains 4 or 5 longitu- 

 dinal intercalar nervures, and an abundance of cross- 

 veinlets 20 



20 Sette d 2 JoUa [?] (p. 42). 



„ .... Set?e d 2, S 3 Fohjmitarcys (p. iS). 



Ephemera Type. 



21 .... Median caudal seta very short and rudimentary 

 in both sexes. Pronotum of ? longer than broad ; fore 



tarsus of 2 subequal in length to the tibia Ilexagenia (p. 48). 



Median seta subequal to the others in both sexes. 



Pronotum of $ somewhat transverse ; fore tarsus of ? 



about f as long as the tibia Ephemera (p. 58). 



Median seta very short and rudimentary in the 



d , but long and little shorter than the others in the 2 . 



Pronotum of $ transverse ; fore tarsus of ? scarcely f 



as long as the tibia Fentagenia (p. 75). 



Potamautlius Type. 



22 .... Median caudal seta long in both sexes .... Potamanthus (p. 78). 

 „ .... Median seta aborted in both sexes Bhoenanthns (p. 81). 



Leptoplilebia Type. 



23 .... Tarsal claws all narrow and uncinate 24 



Of every tarsus one claw is broad and obtuse, the 



other claw narrow and uncinate 25 



24 .... Hind wing more or less obtusely subovate . . . Atalophlebia (p. 83). 

 , Hind wing oblong, oblique ; its marginal area 



abbreviated and relatively very broad Adeiwphlehia (p. 111). 



25 .... Hind wing obtusely ovate or oval; its marginal 



ai"ea narrow throughout and far extended 26 



Hind wing strongly angulated in front ; its mar- 

 ginal area broad and usually abbreviated 27 



26 .... Median caudal seta equal to the others .... LeptopJilehia (p. 91). 

 Median seta much shorter than the others . . . Blastiirm (p. 100). 



27 .... At the roots of the fore wing the 1st Axillar (U^) 



meets the 2nd Axillar nervure Hagenulus (p. 113). 



At the roots of the fore wing the 1st Axillar is 



separate from the 2nd Axillar nervure 28 



28 .... In the Anal- Axillar intersjmce of the fore wing 



SECOND SERIES. — ZOOLOGY, VOL. III. 42 



