EEV. A. E. EATOX ON EECENT EPHEMEEIDiE OE MAYELIES, 309 



Bleptus : Japan, 1 sp. 



Iron: Western N. America, 2 sp. ; Central America (uudcscribed). 



Cinygma : Western N. America, 4 sp. 



Rhithroyena : Europe, 7 sp. and npvvards; N. America, 5 sp. 



Pagnludes: China, 1 sp. ; Tibet, 1 sp. (undescribcd). 



Hepiageiiia : Europe, 4 sp., two of tlicm ranging to E. Amurland, and one undescribed from Segovia ; 

 N. America, 2 sp., and jjrobably many undescribed. 



Compsoneuria : Malay region, 1 sp. 



A kindred genus in N. America (undescribed) may here be enumerated. 



Ecdyurus : N. America, 4 sp. ; Europe, 12 sp. ; the Caucasus, Mesopotamia, Himalaya, and Siberia 

 (undescribed). 



The Ecdyurus type of genera is represented in Cape Colony. An undescribed ? specimen 

 of a species taken by Mr. R. Trimeu at Faarl, and now in M'Lach. Mus., has a superficial 

 likeness to species of Heptagenia, but differs therefrom in the proportions of its legs. Some 

 small undescribed species, not referable to Compsoneuria ^ and of undetermined genus, natives 

 of the Malay region, are represented in a Leyden Collection. 



In tliis volume 55 genera and 270 species of recent Ephemerldce are characterized, in 

 addition to 11 nameless nymphs, and 19 species named by other authors, which cannot 

 now be classified exactly. Amongst them, 5 genera and 08 species were new to science, 

 and 13 of the older species had to be renamed. 



A Conspectus of the Classification adopted in this volume prefaces at pp. 21-22 the 

 systematic description of the Ephemeridce. I now bring it to a close with an analysis of 

 the Grovips, &c., therein set forth. The tabulated characters apply solely to adult 

 insects, and are selected from fuller particulars given at the pages that are indicated, to 

 which reference should be made. 



Analysis of the Group.s, Series, Sections, akd Genera. 



Family EPHEMERID^ (p. 2). 



1 . . . . Group I. (p. 22). At the roots of the mesothoracic wing the Anal (8) 

 nervure meets the Pobrachial (7) nervure; and, when axillar nervures are 

 developed, the 1st Axillar ('J') meets the Anal nervure. Ilinder tarsi usually 

 4-jointed ; when a fiftli joint is traceable, it is only very short, and is intimately 

 blended with the tibia 2 



, Group II. (p. 77). At the roots of the mesothoracic wing [except in 



Series 1 and 3] the Anal (3) nervure communicates only indirectly with the 

 Pobrachial (7) nervure, through an obsolete channel of circulation, discernible 

 in the wing-membrane. Legs all functional [except, perhaps, iu Frosopistoma]. 

 Hinder tarsi usually 1-joiuted; a very short filth joint is sometimes intimately 

 blended with the tibia > . 3 



