1916] Malloch — The Genus Agromyza (Diptera) 53 



inner cross-vein distinctly before end of first vein and two fifths 

 distant from apex of discal cell; outer cross- vein distant about its 

 own length from inner, and very slightly beyond end of first vein; 

 last section of fourth vein about two and a half times as long as 

 the preceding two sections combined; penultimate section of fifth 

 about two thirds as long as last section. Halteres with exception- 

 ally large knob. Length, 2 mm. 



Type locality, St. Joseph, 111., May 17, 1914 (C. A. Hart). 

 Food plant unknown. 



This species will "run down" to varifrons Coquillett in the table 

 previously referred to, but may be separated readily by the color 

 of the frons and by the wing venation. In varifrons the black of the 

 frons is not confined to the orbits and ocellar region, but extends 

 over the central stripe, on its upper third at least. The last section 

 of fifth vein of wing in the same species is subequal in length with 

 the preceding section, and the second costal division is nearly 

 twice as long as the first. 



Agromyza nigrisquama sp. no v. 



Female: Black, subopaque. Wings clear, veins black. Squamse 

 black-brown, fringes concolorous. Halteres yellow, knobs lemon- 

 yellow. 



Frons with center stripe opaque, orbits slightly shining, each 

 about one fifth as wide as center stripe, width of frons at vertex 

 slightly over one third the head width, a little narrowed anteriorly, 

 4 pairs of bristles on orbits, the anterior 2 pairs incurved, the poste- 

 rior 2 pairs reclinate, orbital hairs sparse; antennae of moderate 

 size, second joint with distinct dorsal bristle, third joint rounded; 

 arista bare, tapering at base, its entire length equal to from its 

 base to upper orbital bristle; cheek about one sixth the eye height, 

 marginal bristles weak, vibrissse well differentiated. Mesonotum 

 with 4 pairs of dorso-centrals, the anterior pair in front of suture; 

 no distinct bristles between posterior dorso-centrals; discal setulse 

 in about 8 irregular rows between anterior dorso-centrals. Abdo- 

 men with rather long hairs, especially at apex; ovipositor short, 

 obtuse. Legs slender, the mid tibial setulse present. Wings 

 broad, costa to end of fourth vein; inner cross vein at distinctly 

 beyond middle of discal cell and slightly before end of first vein; 

 outer cross vein at about its own length from inner; last section of 



