18 PROCEEDINGS OP THE NATIONAL MUSEUM vol. 78 



STYLOGASTER BANKSI. new species 



Male. — Frontal triangle extending to middle of front, the latter 

 blackish, a little reddish close to lunule. Antennae brown except 

 lirst joint and extreme base of second; third joint blackish, the 

 apex red below, about one and two-tenths times the length of the 

 second. Mesonotum mostl_y black, which extends in a broad stripe 

 down the mesopleura. Humerus white, adjacent parts brownish. 

 Hind part of dorsum yellowish brown. Scutellum with a dark spot 

 on disk and the extreme lateral corner black. Lower part of meta- 

 notum black in middle. Humeral 1; notopleural 1 (or 2 very close 

 together) ; supraalar 1. 



Abdomen largely black ; first segment black above, lateral bristles 

 numerous, black, arising from a distinctly brownish spot; second 

 segment black except extreme base, with three or four black bristles 

 at the side anteriorly; third and fourth segments with light yellow 

 lateral triangles at base, which in the third reach nearly to hind 

 margin at the side, in the fourth not so extended; fifth segment 

 shining black except basally and along the sides below; sixth seg- 

 ment very narrow, blackish, shining; seventh segment blackish at 

 sides, a conspicuous whitish spot occupying most of its surface 

 and reaching front margin in middle. Genitalia rather pale, the 

 posterior forceps strongly hooked and rather sharp at the tip, the 

 anterior or outer forceps have a long process at tip which closes 

 in repose so as to project on the opposite side for a considerable 

 distance (this, of course, might be concealed in some specimens) ; 

 the posterior forceps are rather far apart at base so as to inclose 

 an oval space partly filled with pale hairs projecting from the 

 forceps. 



Front and middle legs pale yellow, the tarsi a little darker; hind 

 femora yellow at base and tip and with a broad yellow median 

 annulus; hind tibae pale at base, becoming black in middle, the 

 penultimate fifth rather distinctly white, remainder and tarsi black. 

 The erect pile of the inner side of the femur is rather sparse and only 

 extends to about the middle. 



Wing uniformly light brownish, the first posterior cell wider than 

 the marginal; second vein decidedly shorter than usual, ending 

 nearer base of wing than the anterior end of hind cross vein. 



Female. — Ovipositor a little longer than remainder of abdomen, 

 yellow at base, the remainder black, extreme tip and its appendages 

 yellow. 



Length, male 6.3 mm., female 5.5 mm. to ovipositor, which measures 

 3.9 mm. 



Described from 16 males and 10 females, all collected at Barro 

 Colorado Island, Canal Zone, one male by Nathan Banks, the 

 remainder by C. H. Curran. 



