J. R. AIALLOCH 173 



and iiiorr slender tlian usual; fore tarsus with a very loiiji bristle at apex of 

 fifth joint above; bristles on antero-ventrul surface of hind femur more widely 

 separatetl than usual, those on basal half of femur not as lonj; as diameter 

 of femur. Costal thorn short. 



Fnnnlc. — Similar to the female of (imbUjua in fj;encral habitus. M'iie abdo- 

 men is more yellowish, and has a narrower dor.so-central vitta and less con- 

 spicuous checkerings. 



Length, 6.5 to 7.5 mm. 



Type. — d^; Pullman, Wasliinf2;ton, [Illinois]. Alloiiipv. — 9; 

 topotypic. Paralypes. — Same locality, [Coll. Dr. Al(hicli|. Six 

 specimens. 



MACROPHORBIA gen. n. 



(fciicric Cfutrddcrs. — Dilfers from Hylcniijid in having four 

 pairs of post-sutiu'al tlorso-central bristles, the lower calypira 

 almost or quite as large as the upper, the abdomen broadly ovate 

 in male, the mid tibia in both sexes with one or two median 

 ventral bristles, and the cruciate frontal bristles in female dupli- 

 cated. 



Genotype. — Macrophorbia huiujhi sp. n. 



Macrophorbia houghi sp. n. 



Male and fcmnlc. — Black, glossy, thorax and abdomen with I)hiish gray 

 pruinescence. Head black, orbits and face with silvery pruinescence; inter- 

 frontalia in female opaque black. Thorax quadrivittate. Abdomen in 

 male with dense pruinescence on dorsum, when seen from behind with a 

 narrow black central vitta, and a black triangular mark at each anterior 

 lateral angle of each segment; hypopygium glossy black; abdomen of female 

 almost without pruinescence. Legs black. Wings clear. Halteres with 

 yellowish knobs. 



Male. — Eyes bare, separated at narrowest part of frons by a distance 

 less than equal to width across posterior ocelli; parafacial at widest point 

 nearly as wide as third antennal joint, slightly narrowed below; cheek with 

 its [)osterior margin rounded off, the posterior half almost entirely covered 

 with hairs, anterior half with hairs along lower margin only; vibrissa strong, 

 the hairs extending upward on facial ridges about one-third of the distance 

 to base of antennae; third antennal joint broad, about 1.5 as long as second; 

 arista nearly bare, second joint distinctly longer than thick, third swollcm 

 for a short distance at base. Thorax with from two to four pairs of {)r(>- 

 sutural acrostichals; anterior two pairs of post sutm-al dorso-centrals weaker 

 than the posterior; .sternopleural bristles 2:2, some of the hairs near posterior 

 upper angle bristle-like. Abdomen not Lo as long as broad; dorsum rather 

 densely haired; hypopygium large; processes of fifth stcrnite with dense, short 

 hairs along their inner third and long irregular bristles on outer two-thirds. 



TKAXS. AM. EXT. SUC, XLVI. 



