328 REV. A. E. EATON ON EECENT EPHEMEEID^ OR MAYFLIES. 



same from a different specimei), sliowing a forceps-limb, both of the spinules or prickles 



adjacent to the forceps-limb, one half of the siibgenital plate, and the penis-lobes closed 



togetlier (dried). 

 Fig. 8 d. C. cuspidatus : — underside view of J* genitalia (dried) . 

 Fig. 8 e. C. quadridentatus : — underside view of subgenital plate with the right forceps-limb entire ; 



penis-lobes viewed from behind, points upwards; side view of a penis-lobe, point downwards, 



much more enlarged (dried). 

 Figs. 8/. C. curtus : — partial underside view of ^J genitalia, showing the right forceps-limb and the base 



of the left limb, and also the penis-lobes above the halves of the subgenital plate distorted in 



drying. Also two detached figures, much more enlarged, of penis-lobes (dried). 



Plate VI. 



Neuration of 8", a nameless insect related to Campsurus. Also neuration, limbs, external J" genitalia, 

 and head of adult ^ of 10. Polymitarcijs : — all enlarged. 



Fig. 8 bis. Nameless Brazilian insect (M'Lach. Mus.) : — wings. 



Figs. 10 «. P. virgo : — wings; legs (1-3) of adult (^ , with enlarged views of the intermediate and pos- 

 terior tarsi ; fore leg of (^ subimago, on the same scale of enlargement as the adult fore leg ; 

 ventral view of (J genitalia, showing the penis and a forceps-limb ; vertical view of the adult 

 ^ head with part of the pronotnm. 



Fig. 10 6. A S. -African species: — fore wing. 



Fig. 10 c. A N.W. -Indian species : — hind wing. 



Plate VII. 



Neuration, limbs, and external (J genitalia of 11. Hexagenia ; all enlarged. 



Fig. 11 «. A N.W. -Indian species : — fore wing and part of hind wing. 



Figs. 11 b,l\b' and l\h?. H. bilineata : — hind wing and part of a fore wing; three views of single forceps- 

 limbs, each with another view, on rather a larger scale, of the extremity of the limb, illustrating 

 variations in the number and relative size of the smaller joints [of these threCj the two on the 

 right side of the jilate are from dried specimens ; the underside view of the ^ genitalia, on 

 the left side of the plate, is from an alcoholic specimen, and shows the penis-lobes — one 

 shaded, the other in outline]. 



Figs. lie. H. Umbata : — wings; legs (1-3) of each sex;rr genitalia, showing a forceps-limb and a 

 penis-lobe (dried). The remarkable aberration displayed in the neuration of the fore wing 

 here figured is described at the bottom of p. 4. 



Plate VIII. 



Neuration, limbs, and external 6 genitalia of 12. Ephemera and 13. Pentagenia ; also head 



of adult d Epjhemeru. 

 Figs. 12 a. E. danica : — wings ; legs (1-3) of d and (1) of ? , with an enlarged view of the terminal 



joint and ungues of the c? fore tarsus ; forceps viewed from below. 

 Figs. 12 6. E. vulgata : — part of a fore wing; underside view of penis-lobes. 

 Figs. 12c. E. supposita: — underside view of d genitalia, showing forceps and penis; a slightly enlarged 



side view of a penis-lobe (dried) . 

 Figs. 12 d. E. ghmcops; head of adult J, the upper figure being taken from in front of the specimen, 



and the lower from the side. The latter view includes part of the prothorax and of the fore 



leg. 

 Figs. 13. P. vittigera: — wings of both sexes ; legs (1-3) of both sexes; underside view of penis and a 



forceps-limb (dried) . 



