70 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.52. 



of median segment, lateral angles of same, broad fasciae on tergites 

 1-6 interrupted medially, slightly attenuated medially on 1 and 2, 

 and attenuated or interrupted laterally on 2-6, triangular lateral 

 spots on sternites 2-5 joined by faint apical lines, tips of femora with 

 short line extending inward on anterior and posterior surfaces of 

 anterior pair, tibiae except a part or all of the posterior surface of 

 the several pairs, anterior tarsi, yellow. Anterior wings with a 

 heavily infumated spot in region of first cubital cell; antennae and 

 legs without special modifications. 



Female. — Black: Clypeus, base of mandibles, frons below antennae, 

 scape below, anterior orbits not reaching to vortex, posterior orbits 

 narrowed above, posterior margin of pronotum including tubercles, 

 lateral lines on scutum, pair of large diamond-shaped discal spots on 

 same anteriorly, large spot on mesopleura, pair of large rounded spots 

 on scutellum, metanotum, curved fascia on dorsum of median segment, 

 lateral angles of same, broad fasciae on tergites 1-5 interrupted medially, 

 first greatly and second slightly attenuated toward median line and 

 second to fifth attenuated laterally, triangular lateral spots on 

 sternites 2-5, spot on anterior coxae, tips of femora with line both 

 above and below on anterior pair, tibiae except more or less of poste- 

 rior surfaces, anterior tarsi, yellow. Anterior wings with heavily in- 

 fumated spot in region of first cubital cell; apical tergite without 

 pygidial area, sparingly punctured medially, more closely laterally, 

 especially at base, lateral ridges short and feebly developed; apical 

 sternite with faint median carina. 



Length. — 16-18 mm. 



In coloration the males and females of this large and handsome 

 species are very much alike, the markings being a rich yellow in the 

 females and creamy yellow in the males. But little variation is 

 found. The clypeus is predominantly yellow; in the male it is almost 

 invariably so and in the female the black is confined to the apical 

 margin, where it forms a more or less conspicuous border, or may 

 appear as two small median spots. The discal spots on the scutum, 

 variable in size and form, show in the majority of specimens a de- 

 cided rufous color, which color may also appear on the spots on the 

 mesopleurae. The median segment bears on its dorsal surface a 

 curved yellow fascia, broad and conspicuous in the female, much re- 

 duced in width or present as a series of spots in the male. The 

 fasciae on the tergites are all rather widely interrupted. The first is 

 much narrowed medially, the second less so. Contrary to the origi- 

 nal description all these fasciae except the first and occasionally the 

 the last, reach the border of the segments even in the males, in which 

 the fasciae are narrower than in the females. The lateral spots on 

 the sternites may or may not be connected by narrow apical bands. 

 The antennae of the male show no evident modifications but segments 



