Sept., I9I3-] Melander: Synopsis of Diptera. 259 



longer than the inner, the arista one and one half times as long as the antenna. 

 Proboscis short, black, its labella sometimes dusky ; palpi small, narrow, straight 

 and with a single terminal hair. Thorax, scutellum and abdomen metallic 

 green or blue, three pairs of long dorsocentrals, the pubescence normally fine ; 

 abdomen highly polished, last segment of female long, triangular, jet black. 

 Halteres black, calypteres entirely whitish and with white hairs. Legs black, 

 subshining. Wings broad, hyaline, veins black, the costa thickened and vaulted 

 in front of the marginal cell, and vanishing beyond the end of the third vein ; 

 third vein ending slightly in front of the tip of the wing, the fourth vein 

 somewhat diverging from the third and ending beyond the wing apex ; discal 

 cell relatively broad, the anterior crossvein slightly beyond its middle ; outer 

 segments of fourth vein proportioned one to four, segments of fifth vein four 

 to three. 



One male and five females, Wawawai, Washington, May 20, 191 1. 



This species might well be assigned to Rondani's genus Donio- 

 myza, the other species of which are evidently related to the second 

 group of Agromysa, with pale halteres. The present species shows 

 such close relationship to the ccncivcntris group that it should not be 

 separated from these species merely because of an abbreviation of the 

 costa. The species Agroniyza rcptans Fallen and nigripcs Meigen 

 frequently exhibit a thinning away of the costa beyond the third vein 

 and such individuals could very well be classified as Domomyza. 



Agromyza diadema new species. 



Female. — Length 3 mm. Polished black, the front and lunule yellow, noto- 

 pleural and meso-pteropleural sutures very narrowly yellowish. The yellow of 

 the front becoming brown on the upper part, but clearly differentiated from the 

 black orbits and the small ocellar triangle ; sides of ocellar triangle convex. 

 Four reclinate fronto-orbitals, uniformly spaced, the space between them and 

 the eye unusually narrow and nearly devoid of hairs. Face strongly receding, 

 no vibrissal angle, cheeks one fifth the eye-height, a single oral vibrissa ; in 

 profile the front edge of the clypeus is visible ; center of face flattened, scarcely 

 carinate. nor grooved, the edge of the epistome shallowly arched. Antennae 

 nearly reaching the margin of the epistome, the almost bare arista five times 

 the length of the third joint. Palpi and proboscis black, the former broad, but 

 not reaching beyond the oral opening. 



Two dorsocentrals, about eight rows of acrostichals, one presutural, two 

 notopleural, two sternopleurals, one strong mesopleural. Last abdominal seg- 

 ment jet black, flattened, a little longer than the preceding segment, the pro- 

 jecting ovipositor slender, enlarged apically, its upper and lateral edges serrate. 

 Middle tibias with a bristle on the postero-extensor edge below the middle and 

 a smaller one just above. Calypteres whitish, the margin and fringe black. 

 Halteres black, their roots paler. Wings hyaline, veins strong ; costa thick- 



