577 



Female. — Color, orange and black or dark brown. 



Head orange and black, differing from that of the male in having 

 the black of the postclypeus reduced to a dorsal line and that of the 

 labrum to lateral spots ; postocular spots wanting, the caudal margins 

 of the head with a broad orange stripe ; occiput and postgenae pale. 



Thorax : prothora.x as in the male except that the black of the 

 pronotum does not extend as far onto the lateral aspect ; dorsal black 

 stripe of the mesothorax extending on each side of the dorsal carina 

 one-half the width of the supraepisterna; mesopleural suture with a 

 black line, the remainder of the thorax orange and buff; mesostigmal 

 plates as shown in Figure 164. 



Abdomen orange, with narrow basal black rings on terga 2-4 

 inclusive, a longitudinal dark stripe on the caudal three-fourths of 

 five, similar stripes extending the full length of six, seven, and eight, 

 and two triangular spots at the base of the ninth; dorsum of the 

 tenth tergum with a short blunt projection; anal appendages short; 

 ovipositor long and extending caudad of the anal appendages; prostyles 

 short and blunt. 



Measurements 



Length, $ 23 mm. 



Length, 9 24.5 mm. 



Length of abdomen, S 17 mm. 



Length of abdomen, 9 19 mm. 



Length of hind wings, S 10.5 mm. 



Length of hind wings, 9 14 mm. 



Width of hind wings, S 1 mm. 



Width of hind wings, 9 2-2.5 mm. 



This species is rather more common in the southern half of the 

 state than in the northern. It appears on the wing as early as June 20 

 at Urbana, but has been taken at Carmi, June 14, 1915. 



Bibliography 



The following bibliography has been made as complete as possible 

 in literature dealing with the nymphs. The remaining portion is in- 

 tended to include the works referred to in the preceding pages and 

 also the more important systematic publications, such as monographs 

 and catalogues. To persons beginning a study of the Odonata, Mutt- 

 kowski's "Catalogue of the Odonata of North America" and Calvert's 

 ''Progress in our Knowledge of the Odonata from 1895 to 1912" 

 should be considered indispensable. In these two works, most of the 

 literature appearing previous to 1912 is cited. A number of important 



