Calvert: Odonata of the Neotropical Region. 137 

 49. Argia difficilis Selys. 



Argia difficilis Calvert, Biol. Centr.-Amer. Neurop., pp. 84, 369, pis. iv, fig. 15, 

 viii, figs. 42, 42.?, x, 4, 4s. 1902, 1907. 



Habitat : Colombia, Bonda in Dept. Magdalena, June, 1 9, August, 

 1 ?, by H. H. Smith. Carnegie Museum, Pittsburgh. 



For some comparative notes on this species, see under the following. 



50. Argia hasemani sp. nov. 

 { Plate IV, figs. 59, 72, 72s.) 



c?. Rear of the head black, a narrow pale stripe along each eye- 

 margin ; labrum, nasus, and lower part of frons pale (violaceous?). 

 Pale (violet) antehumeral stripe half as wide as the black mid-dorsal. 

 Black humeral stripe at mid-height subequal in width to the pale ante- 

 humeral, forked at its upper end, the mesepimeral branch not reach- 

 ing, the humeral branch reaching, to the upper margin of the sclerite ; 

 a short black line at the upper end of the second lateral thoracic suture. 

 Abdominal segment 2 violet above, a black stripe on each side from end 

 to end of the segment, approaching, but not meeting, its fellow of the 

 opposite side on the dorsum just before the hind end, violet of the 

 anterior part of the segment one-half to two-thirds as wide as the seg- 

 ment itself; 3-7 black, with a narrow transverse basal pale ring, which 

 on 3 is prolonged backward as a narrow violet stripe tapering poste- 

 riorly to two-thirds of the segment's length; a fine pale mid-dorsal 

 line on the greater part of the length of 4 and 5, the inferior lateral 

 margin of 2-7 pale, more narrowly so at the hind ends of 3-7 ; 8-10 

 blue, with an inferior black stripe on each side as long as the segments, 

 in addition to which one male, but not the other, has an anteriorly 

 bilobed black dorsal spot on the posterior half of 8. 



9. Differs from the male as follows : pale predominating (in 2 9) 

 on the rear of the head, owing to the widening of the pale stripes along 

 the eye-margins ; pale antehumeral stripe one-half to three-fifths as 

 wide as the black mid-dorsal ; black humeral stripe three-fifths to two- 

 thirds as wide as the pale antehumeral, shaped as in the male, or (in 

 1 9) forked in its upper half, with the humeral branch a mere line, 

 except at its upper end, where it reaches the upper margin of the scler- 

 ite, mesepimeral branch much wider, not reaching the upper margin 

 of the sclerite ; pale mid-dorsal color on abdominal segment 2 not 

 more than one-fourth to one-third as wide as the segment, pale mid- 

 dorsal stripe on 3-5 reaching from the pale transverse basal ring to 



