no. 2173. A REVISION OF THE BEMBICINE WASPS— PARKER. 8 1 



20. Fasciae on tergites yellow 21. 



20. Fasciae on tergites white primaaestate. 



21. Clypeus yellow similans. 



21. Clypeus black helianthopolis . 



22. First transverse cubital vein but slightly bent; development of ocelli unusual.. 23. 



22. First transverse cubital vein normal; ocellar cicatrices normal 24. 



23. Lateral spots on sternites 2-5 and apex of six yellow U-scripta. 



23. Yellow on tergites limited to lateral spots on 2-4 arcuata. 



24. Frons narrow; eyes divergent at the clypeus; mandibles slender, nearly devoid 



of teeth occidentalis. 



24. Frons normal ; eyes not divergent at the clypeus; mandibles normal 25. 



25. Labrum unusually long (see fig. 217) ; ultimate tergite rugose (see fig. 216) . .rugosa. 



25. Labrum normal ; ultimate tergite not rugose, punctate 26. 



26. Clypeus black or marked with black basally 27. 



26. Clypeus yellow or pale 28. 



27. Labrum yellow; ultimate tergite marked with yellow troglodytes. 



27. Labrum black; ultimate tergite black helianthopolis. 



28. Species large, 17-20 mm.; discal marks on scutum in form of a U, complete or 



broken into spots 29. 



28. Species smaller, under 17 mm.; discal marks on scutum consisting of a pair of 



narrow lines 30. 



29. Second and third sternites broadly banded with yellow; second flagellar segment 



not equal to the combined length of the third and fourth latifrons. 



29. Second and third sternites with only lateral spots; second flagellar segment equal 



to or greater than the combined length of the third and fourth sayi. 



30. Fasciae on tergites yellow similans. 



30. Fasciae on tergites white primaaestate. 



BEMBIX ARCUATA, new species. 

 Figs. 139, 140, 185, 206, 207. 



Male. — Black: Labrum, mandibles except apices, clypeus, scape 

 below, frons except a butterfly-shaped spot below anterior ocellus, 

 posterior orbits prolonged above but not meeting on vertex, pro- 

 thorax, lateral lines, and narrow longitudinal discal lines on scutum, 

 broad fascia on scutellum, fascia on metanotum, curved fascia on 

 dorsum of median segment extending down on posterior surface, 

 lateral angles and sides of same, metapleurae almost completely, 

 spot on posterior part of mesopleurae, anterior part of mesosternum, 

 fasciae on tergites 1-5, first narrowly interrupted medially, the 

 anterior border emarginate on either side the midline, second and 

 third narrowed and interrupted medially, biemarginate on anterior 

 dorsal border and on posterior border curved forward on either side 

 toward the midline, fourth similar in design to the third, fifth con- 

 tinuous and biemarginate on anterior border, median spot on sixth, 

 apex of seventh, greater part of the first sternite, lateral spots on 2-4, 

 greater part of coxae and trochanters, femora except stripe on pos- 

 terior surface, tibiae, and tarsi, yellow. 



The scape is short, broad, and unusually hirsute, and segments 

 6-11 of the flagellum are slightly spinose on the posterior side. As 

 65008°— Proc.N.M.vol.52— 17 6 



