50 WILLIAM J. FOX. 



Metathorax with a long, distiuct, medial furrow. 

 Second subniargiual cell longer than broad, the sides of the first segment, 

 as well as the apical margins of segments 1-5, yellow. Length 10 mm. 



iiiexicaiia. 

 Second submarginal cell almost quadrate ; abdominal segments 1-5 with a 



yellow spot on each side. Length 5 mm ft^inoralis. 



Body, at least the abdomen, reddish. 

 Head and thorax black. 



Dorsulum strongly punctured ; wings, except apex, hyaline agilis. 



Dorsulum glabrous: wing fuliginous, a hyaline spot at apex..RobiiiSOiii. 

 Head, thorax and abdomen reddish, with yellow markings. 

 Antennie much shorter than the head and thorax together, not reaching 

 beyond the scutellum ; vertex and sides of thorax not black. 



elegaus. 

 Antennie reaching beyond the scutellum : vertex and sides of thorax black. 



Cressoiii. 

 MALES. 



Wings fuliginous; size large. 



Abdomen entirely black ; posterior femora reddish bipunctattts. *• 



Abdomen with two spots on second, and the two apical segments entirely 



white texaiia. 



Wings hyaline. 



Body black, more or less marked with yellow. 



Antenna? shorter than the head and thorax together; legs reddish. 



fiilvipes. 

 Antennas as long as head and thorax together. 



Metathorax but slightly sulcate medially ; the femora, except apex, nearly 



always black frateriia. 



Metathorax with a deep medial sulcus; the legs, except the coxje in some 

 species, reddish. 

 Front with a rather strong pit in the middle. 

 Face, clypeus and sides of thorax densely clothed with silvery pile: 



head and thorax subopaque cubensis. 



Face, clypeus and mesopleurse with sparse, silvery pile ; head and 



thorax shining albopicta. 



Front with a medial, impressed line. 



Face and clypeus yellow ; front finely and closely punctured ; the first 

 abdominal segment yellow laterally, as well as on the apical margin, 



inexicana. 

 Face and clypeus yellow; front with large, shallow, separated punc- 

 tures ; the first abdominal segment with a large, lateral, yellow spot. 



loiigipes. 



Face and clypeus black ; front with distinct, separated punctures: all 



the abdominal segments above with a lateral, pale yellow spot; size 



small leinoralis. 



Body, at least the abdomen, reddish. 



Head and thorax black; wings, except apical margin, hyaline. .Robiiisoni. 

 Front and sides of the thorax black; front with large, scattered punctures. 



Cressoui. 

 Front and sides of thorax not black ; front with irregular wrinkles. 



elegaiis. 



