2 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.64. 



deflection of R ^+s about one-half Rg+s] cell 1st Mg open by the atrophy 

 of the outer deflection of Ms] basal deflection of Cn^ immediately 

 before the fork of M; anal veins convergent. 



Abdominal tergites brown, the caudal margin of the segments 

 indistinctly paler; sternites brownish yellow, Male hypopygium 

 with two pleural appendages; outer appendage small, dark-colored; 

 inner appendage pale, the apex irregularly bilobed, the tip of the 

 longest lobe with a few setae. Gonapophyses very powerful, appear- 

 ing as flattened plates, the outer angles produced caudad and mesad 

 into a long, gently curved spine, the extreme tips being contiguous or 

 feebly decussate on the median line. The apparent ninth sternite 

 (ninth tergite) a broad, pale lobe that is distinctly split medially. 



Described from a single male, collected at Ketchikan, Alaska, 

 August 7, 1919 (H. G. Dyar). 



Type.—Vmle, Cat. No. 26078, U.S.N.M. 



ORMOSIA CURVATA, new species. 



General coloration dark brown; basal segment of antenna indis- 

 tinctly pale; halteres with yellowish knobs; \vings grayish yellow, 

 stigma distinct; cell 1st M^ open by the atrophy of the outer deflection 

 oi M^; anal veins divergent; male hypopygium with the outer pleural 

 appendage produced into a long, slender curved point; inner pleural 

 appendage with a powerful spine before the tip. 



Male. — Length about 4 mm.; wing, 5. 4 mm. 



Rostrum and palpi dark. Antennae short, dark brown, the basal 

 segment a little paler. Head discolored, dark, with yellow setae. 



Mesonotum discolored, excepting the anterior part of the prae- 

 scutum which is dark brown. Pleura dark. Halteres obscure yellow, 

 the knobs brighter. Legs with the coxae brownish yellow; trochan- 

 ters yellow; remainder of the legs dark bro^vn, the femora paler 

 basaliy. Wings with a strong grayish yellow tinge; stigma distinct, 

 brownish; veins brown. Venation: Cell 1st M^ open by the atrophy 

 of the outer deflection of M^; anal veins divergent; vein 2dA straight. 



Abdomen dark brown. Male hypopygium with the pleurites stout; 

 outer pleural appendage relatively small, the mesal face produced 

 into a long slender arm that gradually narrows to the cylindrical, 

 chitinized, curved apex; inner pleural appendage appearing as a 

 straight arm, immediately beyond midlength on the lateral or caudal 

 face bearing a powerful, acute, black spine that is but little shorter 

 than the apex beyond it; apex of the appendage pale, incrassated, 

 with the lateral margins feebly chitinized, provided with a single 

 stout seta. Gonapophyses appearing as slender, straight, chitinized 

 rods, the extreme bases swollen, immediately beyond this enlarge- 

 ment on the lateral face ^^^th a smaU chitinized branch. Lobe of the 



