Calvert : Odonata of the Neotropical Region. 147 



by a median perpendicular black line with the black of the nasus ; 

 black humeral stripe similar to that of the male, but not so narrow in 

 its middle where it is subequal in width to the pale antehumeral, the 

 black stripe obsolete on the lower half, or more, of the second lateral 

 thoracic suture ; dorsal blue of the anterior part of abdominal segment 



2 narrower, one-half to one-third as wide as the segment ; 3-5 pre- 

 dominant!}' black in dorsal view, the lateral black stripes wider, so that 

 the mid-dorsal blue is reduced in width to one-third of that of the 

 segment on 3 and 4 and to hardly more than a line on 5, and not 

 confluent with the transverse basal blue ring on 4 and 5, as the ring 

 is mid-dorsally interrupted with black; 6 like 7 of the male ; 8 and 

 9 similar to those of the male, but having in addition a pair of black 

 dorsal stripes extending from the base of each segment to three-fourths 

 of 8, three- fifths of 9, each dorsal fused with its adjacent inferior lateral 

 for the first half of 8 or third of 9, and with its fellow dorsal at the 

 extreme base of 8, but not on 9 ; hind ends of the dorsals narrower 

 and rounded; 10 blue, with a transverse basal black line, posterior 

 dorsal margin of the segment narrowly cleft on the median line almost 

 to the base of the segment. Prothorax and mesostigmal laminae lost. 



cT9. Stigma of the front wings surmounting more than one (55 

 per cent. d\ right wing $ ) or one (45 per cent. d\ left wing 9) 

 cell ; of the hind wings surmounting more than one (50 per cent. cT, 

 left wing 9), one (45 per cent. d\ right wing 9), or less than one 

 (5 per cent, c?) cell. 



Antenodal cells of the front wings 3 (80 per cent. cT, and 9) or 



3 + (20 per cent, c?), of the hind wings 3 (100 per cent. cP, 9 ) 

 The percentages are based on 10 $. 



Dimensions: abdomen d 1 25.5-26, 9 24; hind wing cJ 1 18-20, 9 

 19 mm. 



Habitat : — Brazil, Chapada, by H. H. Smith, 2 cT and parts of 9 

 others, 1 9. Carnegie Museum, Pittsburgh. 



This species is very similar to A. tinctipennis Selys and may be a 

 subspecies (geographical race) thereof, but the intermediates are not 

 at hand. The chief differences are that A. tinctpennis has the black 

 of the frons extending down to the nasus ; the black humeral stripe of 

 uniform width (not narrower in the middle, as in chapada), wider in 

 that it extends over the whole of the mesepimeron (instead of reach- 

 ing to the obsolete first lateral thoracic suture at its upper end only), 

 and not forked, although enclosing a pale dot at its upper end ; the 



