338 Annals of the South African Museum. 



Ante-nodal cross-veins predominantly not coincident in costal and sub- 

 costal space ; two of them always coincident and crossing the double 

 space as triangular membranes. Proximal anal border of hind wings 

 (Anax excepted) excised in males; Literal earkts on second abdominal 

 segment of males ........ Fam. Aeschnidae. 



CA. Eyes separated by a large space (Text fig. 2). Ocelli free or only partly 



covered by a transverse ridge. 



Costal side of triangle not exceeding considerably in length the proximal 

 side. No radial supplement parallel to vein Rs. Female genital opening 

 covered by a vulvar scale. Inferior appendage of male bifid 



Subfam. Gomphinae. 



CB. Eyes contiguous in the median line for a considerable space. Ocelli 



situated at the foot of a frontal vesicle. Costal and anal side of triangle 

 considerably exceeding the proximal side in length. A radial supple- 

 ment roughly parallel to vein Rs. Female genital opening armed with 

 an ovipositor in the manner of Zygoptera. Inferior appendage of male 

 not bifid . ..... . Subfam. Acschninae. 



D. Lateral lobes of labium very large, touching each other in the median line 

 to form a mask-like structure ; median lobe very small ; no second joint 

 to the lateral lobes (Text-fig. 3). Triangles dissimilar in both pairs of 

 wings ; their longer axis in the short transverse axis in the front wing, 

 in the long axis in the hind wing ; very often dissimilar also in position ; 

 distal to the arculus in front wing, at the arculus in hind wing. Ante- 

 nodal cross-veins coincident in costal and subcostal space (except in 

 many cases the last one, which remains limited to costal space) ; all of 

 them equal in structure. Females with vulvar scale. Inferior appendages 

 <>f males not bifid ........ Fam. Libellulidac. 



DA. Proximal anal border of hind wings excised in males ; lateral earlets oil 



second abdominal segment of males. A small projection at the occipito- 

 temporal border of eyes in both sexes. Mcstly iretallic colours on body 



Subfam. Cordulinae. 



DB. Proximal anal border of hind wings rounded in both sexes; no earlets on 



second abdominal segment. 



No distinct projection (indicated in Urothemis) at the occipito-temporal 



border of eyes. Colour system mostly not metallic 



Subfaui. Libellulinae. 



II CA. SUBFAMILY GOMPHINAE. 



Gowphinae are a very homogeneous lot throughout the world iu 

 the superficial (though probably phylogenetically very important) 

 character of colour system. Their numerous species show an infinite 

 variation of a pattern of black and yellow, the black parts of which 

 may pass through many shades of brown to light ferruginous or 

 greyish ochreous in the palest forms, whereas the yellow parts may 

 pass to orange or through various shades of olivaceous to pure green, 

 very rarely to blue. 



