312 EEV. A. E. EATON ON EECENT EPHEMERID.^ OR MATFLIES. 



(9^) nervures run almost parallel with one another to the terminal margin ; and 

 between these nervures and the anal angle, the 2nd Axillar (9") intervenes. 

 Pronotum of minimum proportions B^tisca Type. 42 



12 .... Section 12 (p. 229). Adult unknown 



13 .... Section 13 (p. 230). Hinder tarsi as long as the tibiae, or longer. In 

 the fore wing the 1st Axillar (9^) is almost parallel with, and is near the 2nd 

 Axillar (9') nervure, and it approaches the anal angle . . . Atopopus Type. 43 



Section 14 (p. 233). Hinder tarsi shorter than the tibiai. In the fore 



wing the 1st Axillar (9^) nervure seldom approaches the anal angle so nearly 



as in Section 13 Ecdyurus Type. 45 



Palingenia Type. 



14 .... Axillar nervures well developed in the fore wing ; 

 wing-neuration plentiful ; wing-membrane translucent 



but dull 15 



Axillar nervures obsolescent or wanting in the 



fore wing ; wing-neuration scanty 16 



15 .... Prai'bracbial (C) nervure of the fore wing forked 



beyond the middle ; two conspicuous couples of longi- [(p. 23). 



tudinal nervures proceed to the terminal margin . . . Subgen. Palingenia 



Prfebrachial nervure of the fore wing forked 



before the middle; three conspicuous couples of longi- [(p. 25). 



tudinal nervures proceed to tlie terminal margin . . . Subgen. Anagenesia 



16 .... Wing-membrane dull or satin-like 17 



Wing-membrane " shot " with blue or purple 18 



17 .... Fore wing aiiparently 5-nerved, with the 5th 



nervure forked Oligoneuria (p. 29). 



Pore wing apparently 3-nerved, with the 2nd and 



3rd nervures forked Elassoneuria (p, 32). 



18 .... Pore wing apparently 5-nervcd, with the 4th and 



5th nervures forked SpaiiioplileUa (p. 33). 



Fore wing apparently 4-nerved, with 1st, 3rd, 



and 4th nervures forked Lachlania (p. 34). 



Pore wing apparently 4-nerved, with every ner- 

 vure simple Eomoeoneuria (p. 35). 



Polymitarcys Type. 



19 .... The Anal- Axillar interspace of the fore wing 

 contains numerous sinuate or ogee-curved branchlets 

 of the Anal (8) nervure which run transversely to the 



inner margin. Setae 3 Euthyplocia (p. 36). 



.. .... The aforesaid interspace contains two longitu- 

 dinal intercalar nervures or branches of the Anal (8) 

 nervure, and very few cross-veinlets. Setai 2 . . . , Campsuriis (p. 38). 



