40 A VENATIONAL STUDY OF THE ZYGOPTERA 



3 (2). Area between M4 and Cui just beyond MA generally narrower than that be- 

 tween Cui and the posterior margin of the wing. The quadrangle of the fore 

 wing of the same general shape as that of the hind wing; one may be longer 

 than the other, but if one is widened distally, both are. Sectors of the wing 

 tend usually to be continuous veins, not broken nor zigzag. 



ZYGOPTERA (p. 40) 



4 (1). Fore and hind wings dissimilar, held horizontally in repose. Eyes close to- 

 gether. Supertriangle and triangle present. Males with two superior and one 

 inferior abdominal appendage ANISOPTERA^ 



Key to the Suborder Anisozygoptera 

 Family Epiophlebiidae. Subfamily Epiophlebiinae. 

 I. But one living genus. Characters those of the suborder. Japan and Eastern 



Asia. (Fig. i) Epiophlebia Calvert, 1903 



{Palaeophlebia Selys, 1899) 



Key to the Families and Subfamilies of the Suborder Zygoptera 



1 (8). Antenodal cross-veins 5 or more. Usually cross-veins present in the sub- 

 quadrangle beyond the vein Ac. M3 separating from M1+2 nearer to the arculus 

 than to the subnodus. Nodus usually more than one-third of the distance from 

 the base of the wing to the tip. The quadrangle often crossed. 



(Family Agrionidae) ■ • ■ 2 



2 (3). M not descending the arculus; quadrangle therefore concave anteriorly and 

 at least twice as wide proximally as distally. Basal space crossed. Wings 

 petioled at leasfone-half way to the arculus. Mia closely parallel to IMi. 



Polythorinae (p. 42) 



3 (2). M descending the arculus for some distance; the quadrangle not markedly 

 concave anteriorly, and not twice as wide proximally as distally, at least in the 

 hind wing. Basal space crossed or not. Wings petioled or not 4 



4 (5). Mia parallel to M2. Stigma often atrophied. Quadrangle elongate, often 

 as long as the basal space, and convex anteriorly. Cuo beyond the quadrangle, 

 especially in the hind wing, sends off a branch (Cu2a) to support the area posterior 

 to it, or Cu2 itself bends back to support this area Agrioninae (p. 42) 



5 (4). Mia not parallel to M2, but more or less intermediate between Mi and M2 

 (not in Micromerus) and with rather prominent sectors on either side. Stigma 

 well developed, at least in the hind wing. Quadrangle not so long as the basal 

 space, or if so, not generally convex anteriorly. Cu2a not present 6 



6 (7). Cui and Cu2 well developed veins, A extending as far as the distal end of the 

 quadrangle. M4 generally somewhat curved beyond MA. Stigma usually not 

 much broader distally than proximally Epallaginae (p. 45) 



7 (6). Cui short, not reaching the level of the subnodus. Cu2 reduced to a cross- 

 vein. A following the hind margin of the wing beyond Ac for some distance, 

 then bending forward and ending at the posterior side of the quadrangle. M4 

 not curved beyond MA. Stigma much broader distally than proximally. 



Disparocyphinae (p. 47) 



' Not further discussed in this paper. 



