ABT. 7 AMEEICAN" MUSCOID FLIES IN VIEN-N"A MUSEUM ALDEICH 9 



Female. — ^Length, 9 mm. Eyes slightly but perceptibly hairy. 

 Front broad, 0.37 of head width at the vertex, gradually widening as 

 the face also does to lower curve of eye. Pollen of parafrontals, 

 parafacials, and posterior orbit light golden yellow, which, however, 

 does not extend upon the cheek. Middle of face cinereous, the ridges 

 darker and bristly halfway (one side) or more (the other side) ; 

 cheek one-third of eye height, hairy; proboscis short, fleshy; palpi 

 of usual size, yellow, tips a little swollen. Antennae black, base of 

 third joint reddish; third joint three times the second (not four, as 

 stated by Brauer and Bergenstamm), rather thick at base and dis- 

 tinctly tapering to a small apex; arista bare, its penultimate joint 

 short, thickened to middle. Frontal bristles damaged, only the scars 

 left of many; the usual orbitals are indicated, one ocellar remains, 

 but twisted (?) toward the side. Back of head with white beard, 

 bushy below. Thorax black with bluish-gray pollen; the usual four 

 stripes visible from behind, somewhat coalescing behind suture. 

 Scutellum slightly reddish at tip. Anterior acrostichal % on one 

 side, 2 on the other (lacking the one just before the suture on this 

 side). Scutellum with three large lateral, the apical (scars) far 

 apart and strong; one discal scutellar pair. Supraalar 2; stemo- 

 pleural 1, 1 on one side, the other 2, 1, but the lower small. Abdo- 

 men with nearly uniform bluish-gray pollen, becoming distinctly 

 more yellowish on fourth segment; the hair is coarse and almost 

 suberect. First segment with one pair median marginals ; second 

 with one pair; third with a marginal row of about 10, and a sub- 

 marginal irregular pair on the middle, too far back to be called 

 discals; fourth segment with numerous erect small and large bris- 

 tles beginning near base. In spite of Weidemann's statement, the 

 abdomen shows very little tessellation. Legs black; middle tibia 

 with two bristles on outer front side, the lower large; hind tibia 

 with a row of erect almost uniform bristles on the whole length, 

 just below the middle one considerably larger (on one side, the 

 other has two less enlarged at this place). This does not quite 

 agree with Brauer and Bergenstamm. Wing subhyaline, third vein 

 with two small setules at base; fourth vein with oblique rounded 

 bend, ending considerably before apex. 



The species is exceedingly like Frontina frenchii Williston (syno- 

 nym hesperus Brauer and Bergenstamm, type of Achaetoneura) of 

 the United States, but the latter has bare eyes, four sternopleuralo, 

 three supraalars, and the thira antennal joint is broad to the tip. 

 Not represented in the National Museum. 



