547 



inferiors slightly longer than the superiors, yellowish buff with black 

 tips, the tips directed mesad. 



Female. — Color, similar to that of the male. 



Head similar to that of the male except that the dorsal half or 

 third of the labrum is usually brown. 



Thorax similar in all respects to that of the male ; mesostigmal 

 plates as shown in Figure 216. 



Abdomen with broader dorsal stripes on terga 2-y, all of which 

 extend to the bases of the segments ; terga nine and ten entirely brown 

 except the pale lateral margins ; tergum seven brown, with large blue 

 spots occupying the larger portion of the sclerite and separated from 

 one another only by a mesal line of black; dorso-apical margin of 

 seven and eight blue ; sterna 2-8 with a black mesal line, the eighth 

 with a long apical seta; anal appendages of the usual type, the lateral 

 valves of the ovipositor broad and serrate on the ventral margins; 

 prostyles dark brown, short. 



Measurements 



Length, $ 2G-27 mm. 



Length, 9 26-27 mm. 



Length of abdomen, $ 21 mm. 



Length of abdomen, 9 21 mm. 



Length of hind wings, $ 15 mm. 



Length of hind wings, 9 16 mm. 



Width of hind wings, $ 3.5 mm. 



Width of hind wings, 9 4 mm. 



This species is characteristic of the smaller lakes and larger 

 ponds, the nymphs inhabiting floating vegetation, and the adults flying 

 near the surface of the water close to the habitat of the nymphs. The 

 nymphs do not live in meadow brooks or swift streams. 



Both nymphs and adults were taken at Havana, Illinois, and at 

 Lake Villa during the latter part of June and the first of July. 



Enalxagma hageni (Walsh) 



Nymph. — Color, buff or greenish. 



Head subelliptical, the caudo-lateral angles projecting slightly 

 caudad and armed with a few heavy setae; antennae with the third 

 segment longest, the second longer than the first ; labium, when folded, 

 extending caudad to the second pair of coxae, the mental setae of the 

 median lobe three, the lateral setae usually five, and the marginal 

 setae of the median lobe usually three or four. 



