296 AnnaJs of Hie South African Museum. 



METACNEMIS (Selys, 1863). 



This genus, placed by Selys in his " Legion Platycnemis " (see p. 288) 

 is characterised by some important venational features ; the quadrangle 

 approaching the rectangular form (but less so than in the genera 

 Allocnemis, CMorocnemis and Disparoneura), A* separating from the 

 wing's edge at a level widely proximal to the cubito-anal cross-vein, 

 about three times the length of this vein ; Cu 2 broken at the level of 

 nodus or even proximal thereto ; the antenodal cross-veins being 

 closely set and convergent towards li. Besides these characters 

 drawn from reticulation, the long spines of the legs, the Agrion, not 

 Platycnemis-'like shape of head give to Metacnemis and the small 

 group of allied African species a decided resemblance to the large 

 American genus Argia, a resemblance which might well be one of real 

 affinity and not of mere convergence. 



METACNEMIS VALIDA (Selys, 1863). 



Coll. K. J. Morton : 1 $ , King Williamstown (4 . i . 1908, Miss 

 Fountaine) . 



Mr. Morton very kindly agreed to sacrifice this unique specimen 

 for the purpose of obtaining a good photographic figure of a most 

 remarkable pair of wings as given in Plate VII, fig. 10. 



$ (somewhat immature). Labium broad, median lobe not con- 

 spicuously cleft, nearly semi-circular in outline, with a very small 

 and shallow notch and a fine median suture over the whole length ; 

 very light reddish brown, median lobe whitish. Occiput dull reddish 

 brown. Labrum, anteclypeus, postclypeus, frons and vertex light 

 ferruginous, rather densely covered with long, soft, blackish hair. 

 Postclypeus broad, projecting slightly over the labium, anteclypeus 

 very narrow (perhaps by compression). No transverse ridge on the 

 frons ; in front of base of antennae two transversely oval low tubercles; 

 ocelli very small, the posterior ones on slightly elevated bases. 

 Transverse edge of occiput very long, distance of eyes great. 



First and second antennal joints short, third about three times the 

 length of second ; ferruginous to end of third joint, the rest black. 



Prothorax ferruginous, narrowly obscure in the impressed lines. 

 Structure of posterior lobe very complicated. Hind margin of 

 anterior lobe concave posteriorly in its median third, the almost 

 semi-circular concavity bordered by an elevated ridge, low in the 

 middle, elevated in obtusely triangular blades at the lateral ends ; 



