316 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



and one half times as broad as long, little if any narrowed behind, anterior 

 angles acute, behind rounded. Ventral plate of male not extended upward, 

 the boss apical, pale, and transversely wrinkled, each side the ventral plate 

 shows a pale, shallow impression. The appendages are elongate and. recurved, 

 their tips approximate, each tip with an oval scar on the inner surface. Ventral 

 plate of female but little enlarged, its margin slightly concave in the middle 

 and yellowish, the next segment pale on middle and apical margin. Wings of 

 good size, no cross-veins in apical field, radial sector usually two-branched, 

 upper anastomosis oblique; about ten costal cross- veins. 

 Expanse d* 52 mm.; 9 60 mm. 



OYAMIA NIGRIBASIS, n. sp. 



TYPE. U. S. N. M. ALLOTYPE. M. C. Z. 10,831. Two speci- 

 mens. Manchuria and Korea: Yalu River, 150 to 200 miles from 

 mouth, May 1914 (A. DeC. Sowerby coll.). 



Black, a pale spot on clypeus, and one extending from each hind ocellus to 

 the eye. Basal joint of antenna dark, beyond the antenna is pale for one 

 third to one fourth the way out, beyond black. Wings largely yellow-veined, 

 in female less so, and the membrane darker than in the male, costal area of 

 both yellow. Abdomen yellow, in female blackish on base beneath. Legs 

 bright yellow, with distinct dark bands on the bases and tips of femora and 

 tibia, tarsi dark. Ocellar triangle nearly equilateral; hind ocelli hardly 

 larger than the front one, plainly nearer to each other than to the eyes; lateral 

 bosses elliptic, nearer to hind ocelli than to the eyes, anterior bosses long, 

 out-curved, upper inner ends bent inward. Pronotum about one and one 

 fourth broader than long, a little narrowed behind, corners angulate. Wings 

 fairly long, anastomosis oblique,, about twelve costal cross- veins, four sub- 

 costals; radial sector two or three branched beyond the anastomosis. Tips 

 of male appendages broad, flat, not notched. 



Expanse d" 42 mm., 9 54 mm. 



In this and in 0. flavotincta McLachlan the third joint of the palpi 

 is plainly curved. It is not mentioned in other species, but I persume 

 it is a peculiarity of the genus. 



PERL A DUPLICATA, sp. nov. 



TYPE. M. C. Z. 10,818. Va. : Fairfax Co. ; Newington, 4 June 

 (S. A. Rohwer). 



Pale brown; head largely pale, dark between the ocelli, on middle of lower 

 face, and back of the eyes; basal joint of antennae pale, rest and the palpi 

 brown; pronotum with broad, pale median stripe, most of meso- and the 



