509 



surmounting one and one-half to two cells, the postnodal cross-veins of 

 the front wing sixteen or seventeen, of the hind wing fourteen or fif- 

 teen ; M 2 arising between the sixth and seventh or seventh and eighth 

 postnodals in the front wing and between the fifth and sixth in the 

 hind wing. 



Abdomen black, with pale basal rings on segments 3-7 inclusive, 

 faint dorsal and lateral stripes on one and two, and obscure brownish 

 marks on the last two segments; anal appendages (Figs. 157, 158) 

 consisting of short club-like superiors and broad inferiors with a 

 tubercle on the dorsal margin. 



Female. — Color, light blue (etain blue) or olive-buff, and black. 



Head, with front, genae, and vertex pale blue or buff. 



Thorax light blue or buff ; pronotum blue and black, the propleura 

 with indistinct noto-epimeral suture and without the dorsal marginal 

 line of brown ; median lobes of the notum with a large pale spot on 

 each, and another spot about the same size covering the caudo-mesal 

 angles of the median lobes and the median portion of the caudal lobe ; 

 mesostigmal plate (Fig. 154) with a short, median, acute process 

 which projects caudad over the cephalic margin of the mesepisternum ; 

 mesepimera without the broad, longitudinal, dark stripe of the male, 

 usually blue except the cephalic shoulder which is buff and frequently 

 pollinose ; all of the pleural sutures and the dorsal carina lined with 

 black. 



Abdomen black and blue, the black confined to rather broad dorsal 

 stripes on terga 1-9, black spots on the caudo-lateral margins of 2-6 

 and the whole of sterna 1-8 ; segments nine and ten, with the exception 

 of a dorsal brown stripe, and the lateral valves of the ovipositor yel- 

 lowish ; dorsal margin of the tenth tergum with a deep mesal emargina- 

 tion extending nearly to the base of the segment; superior anal ap- 

 pendages, short, dark, and scarcely longer than the blunt inferiors ; ovi- 

 positor with broad ventrally serrated, lateral valves, the prostyles short 

 and dark. 



Measurements 



Length, $ 42 mm. 



Length, 9 41 mm. 



Length of abdomen, $ 33 mm. 



Length of abdomen, 9 31-32 mm. 



Length of hind wings, $ 26 mm. 



Length of hind wings, 9 26 mm. 



Width of hind wings, $ 5.5 mm. 



Width of hind wings, 9 5.5 mm. 



