EEV. A. E. EATON ON EECENT EPEMERID.E OR MAYFLIES, 311 



.... Seiues 3 OF Group III. (p. 230). The Anal-Axill.ir interspace of the 

 fore Aving- includes the anal augie and part of the terminal margin, and it 

 contains a variable number of longitudinal intercalar nervures [usually four] 

 which are commonly disposed in two couples of unequal length : of these the 

 coujjle next to the 1st Axillar (9') nervure is the longest 13 



5 . • . ■ Section 1 (p. 22). Subcosta of the fore wing, when developed, retired 

 somewhat in a fold of the membrane under the Radius (3). Palingenia Type 14 



Section 2 (p. 26). Subcosta of the fore wing displayed (except in the 



dried $ Campsurus) Polymitarcys Type. 19 



6 • . . . Section 3 (p. 18). In the fore wing the Anal (8) and essentially simple 

 2nd Axillar (9") nervures bound a semi-sagittate space. [Compare Section 1, 

 infra.'\ Forceps-basis of s developed ; basal joints of the limbs shorter than 

 the next joints : lol)e of the 9th ventral segment of ? undeveloped. 



Ephemera Type. 21 



7 . . . . Section 4 (p. 78). In the fore wiug the Anal (8) and forked 2nd AxUlar 

 (9") nervures bound a semi-sagittate space. Basal joint of 6 forceps-limb the 

 longest of all. [Compare section 3 su2:)ra.~\ Potamanthtjs Type. 22 



8 . . . . Section 5 (p. 82). In the fore wiug the Anal (8) and simple 2nd Axillar 

 (9') nervures bound a trilateral somewhat Icg-of-muttou-shaped space. The 1st 

 Axillar (9') at its proximal extremity, where it meets the transverse crease in 

 the wing-membrane, is nearer to the 2nd Axillar than to the Anal nervure. [In 

 Eageniiliis the 1st Axillar meets the 2nd Axillar nervure.] 



Leftophlebia Type. 23 



Section 6 (p. 122). In the fore wing the Anal (8) and simple 2nd Axillar 



(9") nervures bound a curved trilateral space, truncate at its narrow end. The 

 Anal (8) and 1st xlxillar (9^) nervures converge, and at the base of the wing lie 

 close together, or in mutual contact, apart from the 2nd Axillar and from the 

 Pobrachial (7) nervure Ephemerella Type. 31 



9 . . . . Section 7 (p. 137). In the mesothoracic wing the Anal (8) and 2nd 

 Axillar (9^) nervures bound a curved trilateral space, truncate, or abrupt at 



its narrow end. Hind wings absent C^xis Type. 32 



Section 8 (p. 149). AVing-neuration imperfectly elucidated. Hind 



wings developed Prosofistoma Type. 34 



. . . . Section 9 (p. 153). In the mesothoracic wing the Anal (8) and 2nd 

 Axillar nervixres bound a trilateral, somewhat leg-of-mutton-shaped space, 

 abrupt at its narrow end. Hind tarsus ^ to | the length of the tibia, 4-jointed, 

 with the proximal joint long Baetis TyjK^ 35 



1 . . . . Section 10 (p. 200). In the fore wing the Anal (8) ncrvvire terminates 

 close by the anal angle ; the 1st Axillar (9') nervure terminates in or before the 

 middle of the inner margin. Pronotum well developed . . Siphlurus Type. 37 



Section 11 (p. 226). In the fore wing the Anal (8) and the 1st x\.xillar 



