Calvert : Odonata of the Neotropical Region. 135 



the antennae to the nasus in the form of a median perpendicular line, 

 or of a wider stripe ; in all cases where the segments are present, 3-5 

 have the mid-dorsal blue stripe (not line) reaching to at least half ■>{ 

 the length of each segment, and 6 has a blue line reaching to one-fourth 

 length. The length of the hind wing varies from 19.5 to 23 mm. 



Habitat : Brazil, Ch pada, by H. H. Smith, 3 tf and parts of 10 

 others, some numbered 186, 187 ; parts of 8 9, some numbered 186, 

 186a, 186b. Carnegie Museum, Pittsburgh. 



48. Argia mollis. 



(Plate IV, fig. 61.) 



Argia mollis Hagen in Selys, Bull. Acad. Belg. (2) xx, p. 398. 1865. Hagen 

 & Calvert, Bull. Mus. Comp. Zool. xxxix, p. 112, pi. 1, figs. 14, 14^7. 1902. 



c?. The males referable to the above-quoted description and figure 

 show the following slight differences from the former : prothorax often 

 with a pair of dorsal blue spots on the middle lobe, a black stripe on 

 the entire length of the second lateral thoracic suture, the dorsal oval 

 violet spot reaches the hind end of abdominal segment 2, 3 has a 

 narrow mid-dorsal violet stripe, tapering posteriorly, for more than 

 the anterior half of the segment ; abdomen 27-29, hind wing 20-21 

 mm. 



The following details may also be added : Black of the frons ap- 

 parently extending down between the antennae to the nasus, but its 

 outlines in the present material are often difficult to trace ; 8-10 have 

 an inferior black stripe on each side as long as the segments; antenodal 

 cells on the front wings usually four, on the hind three. 



There is much variation in the black humeral stripe from the con- 

 dition (a) where it is, at mid-height, one-and-one-half times as wide 

 as the pale antehumeral, wider at both ends, its width at the upper 

 end extending from the humeral suture to the obsolete first lateral and 

 enclosing a small pale spot; through (<£), where at mid-height it is only 

 half as wide as the pale antehumeral and is forked for its upper half or 

 less, the mesepimeral branch reaching up only seven -eighths of the way 

 to the upper margin of the sclerite and curved toward, but stopping 

 short, of the obsolete first lateral suture (on the upper end of which latter 

 is a short isolated black line), the humeral branch a line except at its 

 upper end where it reaches the upper margin of the sclerite ; to (c), 

 where the mesepimeral branch reaches up only three-fourths of the 

 way to the upper margin of the sclerite and is not all curved toward 



