316 EEV. A. E. EATOX OX EECEXT EPHEMEMD.E OK MAYFLIES. 



copious neuration. Hind tarsus probably rather longer 



than the tibia. Median caudal seta long Ametropus (p. 231). 



Axillar region of tlie hind Aving small, narrow, 



and with sparse neuration. Median caudal seta aborted 44 



44 . • • . Hind tarsus of J twice the length of the tibia . A tojwjnis {p. 232). 

 Hind tarsus of 6 equal in length to the tibia . Thalerosphyrus (p. 232). 



Ecdyurus Type. 



45 - ■ . • First joint of the hind tarsus longer than the 



second; the second joint longer than the third 46 



First joint of the hind tarsus equal to the second 



joint 48 



First joint of the hind tarsus shorter than the 



second joint 50 



46 .... First joint of the fore tarsus rather longer than 



the second joint. Hind wings unusually small . . . Bleptus (p. 243). 

 First joint of the fore tarsus equal to the second 



joint. Hind wings well developed Epeorus (p. 237). 



First joint of the fore tarsus shorter than the 



second joint. Hind wings well developed 47 



47 .... Penis-Iolies (when dried) narrow and shrunk to 

 peg-like projections. Femora sometimes without mark- 

 ings, sometimes faintly banded Cinygma (p. 247). 



Penis-lobes (when dried) stout, dilated at their 



extremities. Cross-veinlets scarce in the fore wings. 



Femora banded - Conipsoneuria (p. 275). 



Penis-lobes stout, usually transversely and 



broadly dilated at their extremities, but sometimes ob- 



ovate. Cross-veinlets abundant in the fore wings. 



Femora often banded, but sometimes without markings Ecdyurus [part] (p. 276). 



48 • ■ . Second joint of the hind tarsus equal to the third 

 joint. Femora usually marked with a dark median spot, 

 but banded in one species and without markings in 



another Iroii (p. 244). 



Second joint of the hind tarsus longer than the 



third joint 49 



49 .... Penis-lobes (when dried) narrow and shrunk to 

 peg-like projections. Femora usually marked with a 

 dark median spot or streak, but sometimes without 



markings Bhithrocjena (p. 250). 



Penis-lobes stout and broadly dilated at their 



extremities, or obovate. Femora often banded, but 



sometimes without markings Ecdijurus [part] (p. 276). 



