520 PROCEEDINGS OF THE ACADEMY OF [1895. 



26. Flagellum long, setaceous; scape elongate much more than 



twice as long as broad at apex; middle segment with two 



yellow spots atricornis. 



Flagellum shorter, a little clavate; scape short but little more 

 than twice as long as its width at apex, middle segment 

 not spotted canalieulatus . 



27. Extreme base of enclosure of middle segment only striated . . 28 

 Entire enclosure covered with striae 29 



28. Wings scarcely yellow the stigma testaceous; markings palish 



yellow; dorsal segments 4 and 5 impunctate .... simillimus. 

 Wings with a tolerably yellow tinge, the stigma yellow; 

 markings bright yellow; dorsal segments 4 and 5 with scat- 

 tered punctures angustatus var. 



29. Antennae with the flagellum distinctly thickened apically, 



yellowish beneath, at least basally angustatus. 



Antennae sleuder, the flagellum setaceous, obscure testaceous 

 beneath nevadensis. 



30. Dorsal segments 4 and 5 impunctate 31 



Dorsal segments 4 and 5 with distinct, scattered punctures . . 35 



31. Suture between dorsulum and scutellum foveolate 32 



Suture between dorsulum and scutellum not foveolate 



phaleratus. 



32. Wings, in greater part, dark fuliginous 33 



Wings yellow ferruginous venustus. 



33. Wings clear at apex; first two segments almost entirely 



yellow abdominalis. 



Wings entirely fuliginous; only the first segment spotted 

 with yellow 34 



34. Head and thorax black, ornamented with yellowish; clypeus 



black; first dorsal segment entirely yellow Smithii. 



Head and thorax reddish-brown, including the clypeus; first 

 segment yellow at apex, otherwise colored like thorax, floridanus. 



35. Wings subfuscous ; clypeus entirely yellow ; middle segment 



entirely black, pygidial area with sparse, shallow punc- 

 tures bipartitus. 



Wings hyaline, the marginal cell excepted; clypeus with base 

 only yellow; middle segment with two rufous spots; 

 pygidial area with deep, closer punctures . . . rufomaculatus 



Males. 



Antennae strongly clavate; hind tarsi unusually long and 

 graceful moneduloides. 



Antennae not strongly clavate; hind tarsi not unusually long . 2 

 2. First segment of abdomen coarctate at apex (abdomen black, 

 the second and third dorsal segments with a lateral pale 

 spot) bipunctatus. 



First segment not coarctate, sessile or subpetiolate 3 



