140 Annals of the Carnegie Museum. 



52. Argia smithiana sp. nov. 

 (Plate IV, figs. 64, 74, 745.) 



<3\ Rear of head chiefly black, a fairly wide pale stripe along each 

 eye-margin, its upper end prolonged mesad as a narrower stripe 

 behind the black, which bounds the postocular spots posteriorly. 

 Black of the frons not reaching as far down as the base of the antennae, 

 first antennal joint pale anteriorly, a black line on the fronto-nasal 

 suture, rhinarium dark. Pale (violet) antehumeral stripe at mid-height 

 one half as wide as the black mid-dorsal. Black humeral stripe of 

 subuniform width, or a little wider at the two ends, at mid-height 

 equal in width to, or one and one-fourth times as wide as the pale 

 antehumeral, its upper third to two-fifths forked, both branches reach- 

 ing the upper margin of the sclerite, humeral branch much narrower 

 than the mesepimeral, which curves backward (caudad) to reach the 

 upper end of the obsolete first lateral thoracic suture. A black line 

 on the second lateral thoracic suture down to the metinfraepisternum. 

 Dorsum of abdominal segment 2 violet, a black stripe on each side as 

 long as the segment, widening mesad a little before the hind end of 

 the segment, but not meeting its fellow of the opposite side on the 

 dorsum, and again narrowing; dorsal violet at its widest about two- 

 thirds (or three-fourths, young) as wide as the segment ; side of the 

 segment below the above-mentioned black stripe pale, with an ill- 

 defined longitudinal black stripe confluent at one or two points with 

 the superior stripe and also at the hind end of the segment with a 

 narrow black stripe, which margins the side of the segment inferiorly ; 

 these last two stripes rudimentary in young individuals. Segments 

 3-7 black, a narrow pale (blue or violet) transverse basal ring, which 

 on 3-4 or 6 is confluent with a mid-dorsal blue-violet stripe reaching 

 to four-fifths or five-sixths of 3, half to three-fourths of 4, one eighth 

 to one half of 5, one eighth of 6, or absent on 5 and 6, narrowing 

 posteriorly ; in mature individuals the sides of 3-7 are entirely black, 

 or with only a small trace of pale color at three-fourths' length on 

 3-6, but younger individuals show that this black is due to a fusion 

 of the wider superior black with an originally separate inferior black 

 line extending from just behind the pale transverse basal ring to about 

 two-thirds of each segment's length ; 8-10 blue, with an inferior black 

 stripe on each side as long as the segments. 



9. Differs from the male as follows : A pair of indistinct dark spots 

 on the nasus, pale antehumeral stripe blue in some, the forking of the 



