498 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 58. 



122. Tegulae yellow or testaceous; very rarely brown in the male, and then 



suturiform articulation is very broad and foveolate, the posterior mar- 

 gin of the second abdominal tergite distinctly curved posteriorly to- 

 ward the sides, and the two basal tergites and the base of the third 



coarsely rugose; hind femora always testaceous 148. 



Tegulae brown or black ; posterior coxae always black ; hind femora some- 

 times black 123. 



123. All femora entirely brownish-black; all tibiae entirely dark brown; sec- 



ond abdominal tergite almost entirely smooth and shining. 



123. hallii (Packard). 

 At least the fore femora partly yellowish ; tibiae mostly pale 124. 



124. Radius of forewing much shorter and stouter than the transverse cubitus, 



and making a strong angle with the latter, a distinct knob at the point 

 of union ; second abdominal tergite very smooth and shining ; posterior 

 coxae wholly impunctate and highly polished; posterior femora pale. 



124. atalantae (Packard). 



Radius of forewing not so short and stout; otherwise not combining all 



the above characters 125. 



125. Posterior femora variable in color, often black or blackish; if mostly 



yellowish, inner spur of posterior tibiae is longer than the outer and a 

 little longer than half the metatarsus; first abdominal tergite always 

 distinctly broader at apex than at base, the second never subtriangular 



or strongly narrowed at base 126. 



Posterior femora always yellowish or testaceous ; inner spur of posterior 

 tibiae not, or indistinctly, as lortg as half the metatarsus, and often not 

 longer than the outer spur ; first abdominal tergite sometimes not 

 broader at apex than at base, the second sometimes subtriangular__141. 



126. Stigma short and broad, the radius arising in the middle and perpendicular 



to the anterior margin of the wing; first and second abdominal tergites 

 partly, the third and following entirely, smooth and shining; posterior 



femora black or blackish 125. theclae Riley. 



Not the combination of characters noted above 127. 



127. Second abdominal tergite largely smooth and shining ; hind femora always 



brownish-black or black in the male, sometimes in the female ; when 

 hind femora are yellowish (some female specimens) abdomen is com- 

 pressed on apical half, and the antennae are as long as the body. 



126. elect rae (Viereck). 



Second abdominal tergite usually entirely roughene<l ; if mostly smooth, 



not combining the above characters 128. 



128. Posterior femora black or blackish; rarely testaceous in the female, and 



then the abdomen very suddenly and sharply compressed on the apical 

 half, and the hypopygium projecting distinctly beyond the apex of the 



last dorsal segment 129. 



Posterior femora mostly testaceous; abdomen never so strongly and sud- 

 denly compressed ; hypopygium never projecting beyond apex of last 

 dorsal segment of the abdomen 134. 



129. Third abdominal tergite more or less roughened on basal half; all coxae 



and trochanters, and the hind femora, black 130. 



Third abdominal tergite entirely smooth and polished 131. 



130. Mesoscutum and disk of scutellum very shallowly and indistinctly punctate, 



strongly shining; radius of forewing perpendicular to anterior margin 

 of wing, not tending outward, and with no knob at the point of union 

 wnth the transverse cubitus 127. melanoHcelus (Ratzeburg). 



