112 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.52. 



and emarginate anteriorly on either side the midline, sixth continu- 

 ous, small lateral spots on ultimate tergite, posterior lateral spots on 

 sternites 1-6 the more anterior ones usually connected by narrow 

 apical lines, spot on anterior and middle coxae below, femora except 

 broad stripe above and basally below, tibiae except stripe below on 

 anterior and middle pairs and on posterior border of anterior pair, 

 and tarsi, white, more or less strongly tinged with yellow on head 

 and legs. 



Segments 4-11 of the flagellum bear specialized areas on their 

 posterior surface, which, on the more apical ones, take the form of 

 shallow pits. The apical segment is not curved, is a trifle longer than 

 the preceding segment, and is about equal to it in width. The 

 middle femora are smooth. The second sternite usually bears a more 

 or less well developed median carina, but sometimes this is entirely 

 lacking. The sixth bears a well developed process, broadly trian- 

 gular basally and sharply pointed posteriorly; the seventh bears an 

 evident median longitudinal carina which is bordered on either side 

 basally by a shorter one. 



Female. — Black: Labrum except a medial stripe or basal spot in 

 some specimens, clypeus except a pair of basal spots that may be 

 contiguous, mandibles except apices, scape below, space between 

 insertions of antennae, small rounded spot on either side anterior 

 ocellus, sometimes spot beneath it, anterior orbits, posterior orbits, 

 posterior border of pronotum continued on the sides of prothorax and 

 including tubercles, also spot on sides of prothorax, spot on tegulae, 

 usually small spot above base of wings on scutum, small lateral spots 

 on scutellum, spot on sides of median segment near lateral angles 

 and another on metapleurae not always present, narrow rectangular 

 spot on mesopleurae, fasciae on tergites 1-5, first broad and inter- 

 rupted and somewhat narrowed medially, second continuous inclos- 

 ing a pair of elliptical black spots dorsally and constricted medially, 

 remaining fasciae interrupted or continuous, biemarginate on anterior 

 border and curved forward on posterior border on either side the 

 midline, lateral spots on sternites 1-5 which may or may not be con- 

 nected by apical lines, spot on anterior and middle coxae below, 

 femora distally more or less, tibiae except stripe below and also stripe 

 on posterior border of anterior pair, and tarsi, yellowish white or pale 

 yellow. 



Length. — 15-18 mm. 



In both sexes the head, thorax, and abdomen are covered with 

 rather short and dense pale pubescence, shorter on scutum and 

 abdomen except the basal segment. The wings of the female show 

 a slight infumation medially; those of the male show hardly a trace of 

 this. The females invariably have the two black spots on the base 

 of the clypeus, but these spots vary in development. On some 



