492 PROCEEDING,^ OF THE NATIONAL MUSEUM. vol.52. 



spine. Genital valves long, extending beyond apex of 10, denticulate 

 along their ventral edge, stylus equaling appendages in length. (See 

 figs. 30-31.) 



Male, live color. — Labrum greenish blue, edged above with black. 

 Base of mandible greenish blue edged basally with black. Nasus, 

 vertical surface of frons, genae and base of mandibles greenish blue. 

 Post-clypeus, dorsal surface of frons and vertex black, except the 

 large, triangular, pure blue postocular spots. Rear of head black 

 but edged along the ocular border with a wavy line of blue. Labium 

 pale brown. Eye, upper half black with an anterior blue horizontal 

 stripe, lower half greenish gi-ay, the hne of demarcation abrupt, but 

 not a sharp hne. (See fig. 19.) 



Prothorax black, with a wide triangular spot on the anterior lobe, a 

 minute spot on the middorsal hne of the anterior edge of the middle 

 lobe and a small spot on each lateral end of the posterior lobe, pure 

 blue. A dumb-bell-shaped pale brown spot on the lower side of the 

 prothorax. 



Mesothorax and metathorax with the anterior surface black, ex- 

 cepting a broad interrupted antehumeral stripe resembUng an inverted 

 exclamation point, pure blue. Sides pure blue except the lower end 

 of the metepisternum shading into pale brown and the following 

 black markings : All alar ridges broadly black, the black of the mese- 

 pisternum overlapping the humeral suture and forming a narrow 

 posthumeral stripe wliich abruptly widens below into a square spot 

 on the lower end of the mesepimeron. A narrow wedge of black 

 running dowm on the upper sixth of the first lateral suture. Second 

 lateral suture broadly black, the dorsal third of this stripe dilated into 

 an oval spot, the ventral end of the stripe continuous with an irregular 

 black area on the anterior end of the metepimeron. Lateral meta- 

 sternal keel broadly black. Mesmfraepisternum black except ventral 

 thu-d brown. Metinfraepisternum brown but broadly edged with 

 black above. Ventral surface of thorax pale brown. All coxae 

 black on their external and posterior surfaces (with usually a narrow 

 brown spot on the ridge between these surfaces), their mesal sm-faces 

 brown. Trochanters and femora black externally, pale brown inter- 

 nally j tibiae and tarsi black. Wings hyaline ; stigmas black. Abdo- 

 men black with blue and pale-brown markings. Segment 1 pure 

 blue, except a baso-lateral, rectangular, black spot and a narrow 

 apical, vertical stripe on each side. 



Segment 2 black, except a pure blue rectangular spot occupying 

 the anterior two-thirds of the dorsum and a broad greenish blue stripe 

 along the ventral edge of the side. 



Segments 3-6 black, except a narrow pale brown, basal ring, inter- 

 rupted middorsally (but sometimes obsolete on segment 3) and a nar- 

 row pale-brown stripe along the ventral edge of the side. 



