330 EEV. A. E. EATON ON EECENT EPHEMEEID^ OR MAYFLIES. 



Figs. 20. Th. bellus : — wings, with part of a fore wing, and a more enlarged view of the hind wing; legs 

 (1-3) of cj, with more enlarged views of the intermediate and hind tarsi; underside view of 

 forceps, and of penis (from specimens in fluid). 



Plate XIII. 



Neuration, limbs, and external ^ genitalia of 20*. Thravlus (provisional) [including 23*. CalUarcys 

 (provisional)], 21. AdenojMebia, and 22. Habrophkbia. — [For 23. Caliarcys (proper) see 

 Plate XIV.] 



Figs. 20*^. Th. exigims : — wings, with a more enlarged view of the hind wing ; one of the hinder tarsi; 

 underside partial view of ^ genitalia, with another more enlarged view of the penis (dried). 



Fig. 20*'. Th. colonibice : — hind wing, much enlarged. 



Figs. 21. A. dislocans : — wings ; legs (1-3) of ^ , with a more enlarged view of the intermediate tarsus; 

 a forcejjs-limb and an underside view of the penis (dried). 



Figs. 22 «. H.fusca : — wings; legs (1-3) of c?, with more enlarged views of the hinder tarsi; underside 

 view of the forceps, and of the penis (freshly killed) . 



Figs. 22 b. H. modesta : — side view and underside view of penis (dried). 



[Figs. 23*", 23*', and 23*', referred provisionally to Calliarcys in the writing on the Plate, are cited in 

 the descriptive letterpress at pp. 109-110 under Thraulus.'] 



Figs. 23*°. A nameless insect : — wings, with a more enlarged view of the hind wing. 



Figs. 23*\ Th. Icetus : — part of a fore wing ; one of the hinder tarsi ; partial underside view of the 

 penis and a forceps-limb (dried). 



Figs. 23*'. Th. mewicanus : — hind wing, much enlarged; underside view of the penis and a forceps- 

 limb (dried). 



Plate XIV. 



Neuration, limbs, and external $ genitalia of 23. Calliarcys, and 21. Ephemerella ; also adult 



^ head of the latter : — all enlarged. 



Figs. 23. C. humilis : — wings, with portions of two fore wings, illustrating differences in the inter- 

 calary nervures of the aual-axillar interspace, and a more enlarged view of the hind wing ; legs 

 (1-3) of cJ and the fore leg of ? , with more enlarged views of the 2 fore tarsus and the hinder 

 cJ tarsi ; underside view of forceps and penis (from a specimen in fluid) . 



Figs. 24 a. E. ignita : — legs (1-3) of cJ and fore leg of $ ; underside view of forceps and penis ; head 

 of c? viewed from above, from the side, and from in front (freshly killed) . 



Figs. 24 b. E. grandis, a N. -American species : — wings, with part of a fore wing showing an unusual 

 arrangement of the neuration, the longest of the adventitious nervures (7') included between 

 the pobrachial (7) and the anal (8) nervures, meeting this last instead of the pobrachial nervure; 

 a more enlarged view of the hind wing. 



Fig. 24 c. E. invaria : — underside view of penis (dried). 



Plate XV. 



Neuration of 21 bis. Hagenulus, 24 bis. Teloganodes, 25. Tricorythus, 25 bis. Leptohyphes, 26. Canis, and 

 (after Vayssierc) 27. Prosopistoma, with limbs and genitalia of Hagenulus and Canis, and head 

 of adult (J of tills last. 



Figs. 21bis. H. caltgatus : — wings, with a more enlarged view of the hind wing ; legs (1-3) of ? and 

 fore leg of ^J, with more enlarged \dews of the (J fore tarsus and $ hind tarsus; penis with a 

 slightly enlarged view of one of its divisions in a different posture ; one of the forceps-limbs 

 (dried). [This ^ im. should be ranked with the 4 $ imagines mentioned at p. 114, line 13 

 from top. j 



