A. A. GIRAULT. 3 



nipple running proximad and slightly' caudad curving near its base disto- 

 caudad to form a shorter, broader nipple, then from the apex of this 

 straight proximad to form the inner (caudal) edge of the marginal vein. 

 Sculpture of the body alutaceous, inconspicuous, combined with deli- 

 cate minute longitudinal striation (balsam mounts), in reality delicate 

 polygonal figures over the whole body, including portions of the ab- 

 domen ; fore wings widest at distal fourth, the marginal cilia longest 

 at the distal end of the caudal wing margin, there not as long as the 

 longest marginal cilia of the posterior wing, only about as long as a 

 seventh or eighth of the greatest wing width. 



Antennae short, moderately stout, with scattered soft pubescence. 

 Scape cylindrical, much longer than the pedicel or the basal club joint, 

 but not especially long or slender ; pedicel long-obconic, about equal 

 to the proximal club joint in length or slightly longer, about two-thirds 

 the length of the scape; ring-joint distinct, short and narrow, button- 

 like ; the 2-jointed club forming about half of the whole antenna, 

 cylindrical-ovate or spindle-shaped, its proximal joint obconic, widen- 

 ing distad, wider than the pedicel and about a fourth shorter than the 

 distal joint, which is conic, truncate and broad proximad and tapering 

 to a point ; club distinct, broader than the scape and pedicel. Articu- 

 lation between the two club joints not very distinct. 



Male. The same as the female with the exceptions as noted under 

 the generic description and this : the fumation of the fore wing is not 

 broken by a narrow oblique clear streak. 



From 2 male and 27 female specimens, |-inch objective, 

 1-inch optic, Bausch and Lomb. 



From the naked eye visible but not recognizable. Through 

 a hand-lens (Coddington, 5-inch, Bausch and Lomb) as pre- 

 viously described as concerns coloration, but when casu- 

 ally glanced at, appearing as if the wings were very short 

 and triangular and black, the remaining hyaline portion not 

 showing. The characteristics of this beautiful species are 

 the half clouded wings and the varicolored — dusky shining 

 black and yellow — body, especially the peculiar half and 

 half coloration of the head. 



Described from 1 male and 26 female specimens mounted 

 in balsam, the coloration and sculpture taken from living 

 specimens stupefied with chloroform and captured on the 

 panes of a small window in an empty pig-shed on a farm at 

 Centralia, Illinois, August 25 (1 9 ), 26 (1 c^, 2 9 's), 29 (1 

 9 ), 31 (1 9 ); September 3 (1 9 ), 4 (4 9 's), 5 (2 9 's), 6 



TRANS. AM. KNT. SOC. , XXXVII. 



