ART. 8 REVISION OF THE FLY GENUS BELVOSIA ALDRICH 1 1 



of these specimens were compared by Prof. A. L. Melander with the 

 single female type of slossonae, formerly in the collection of Mrs. Annie 

 Trumbull Slosson, but now in that of the American Museum of 

 Natural History. It was collected by Mrs. Slosson at Charlotte 

 Harbor, Fla. 



BELVOSIA SEMIFLAVA, new species 



Male. — Front at vertex 0.40 of the head width, widening only a lit- 

 tle for a short distance. Frontal bristles in three irregular rows, the 

 parafrontals with white pollen becoming thinner and more gray above, 

 the upper part black and subshining; face, parafacials, cheeks, and 

 posterior orbits silvery white. Face rather narrow. The hairs below 

 the frontal bristles are pale with a yellow tinge. Cheek almost half 

 the eye height, with pale hairs. Antennae nearly black, basal joint 

 somewhat paler, the third joint a little more than twice the second- 

 Vibrissae rather high above the mouth, facial ridges with half a dozen 

 small bristles reaching about halfway up their length; palpi rather 

 dark yellow, in some specimens brown. Beard white. 



Thorax black, not much pollinose except in front; scutellum more 

 brownish. 



Abdomen deep black on first two segments, not very shining, the 

 remaining two entirely covered with deep yellow pollen. First and 

 second segments with a single pair of median marginals, third and 

 fourth with marginal rows of about 10. 



Legs black; front pulvilli elongated, but scarcely equal to the last 

 two tarsal joints. Hind tibia with suberect row of bristles on outer 

 hind side, one larger below middle. 



Wings brown, except toward base; calypters decidedly bro^\n. 



Female. — Front at vertex 0.40 (in two) of the head width; third 

 antennal joint twice the second. 



Length, 11-13 mm. 



Described from 25 specimens of both sexes. The type and allo- 

 type are from Rio Ruidoso, White Mountains, N. Mex., collected July 

 19, on flowers of Rhus glabra (Townsend); 15 specimens from Kan- 

 sas (Bourbon, Franklin, Linn, and Cheyenne Counties; R. H. Beamer, 

 Williams), received from University of Kansas; 1, Agricultural Col- 

 lege, Miss. (Wheeler); 3, Clemson College, S. C. (Conradi); 1, Oak 

 Grove, Va. (Townsend); and 3 from the Kansas collection labeled 

 "W. T."in not very legible writing. I take these labels to be in 

 Williston's handwriting and to mean Washington Territory, but as 

 the species is common in Kansas and not otherwise known from the 

 Northwest I fear a mistake in labeling has occurred. 



Type.—M&le, Cat. No. 40467, U.S.N.M. 



BELVOSIA MEXICANA, new species 



Male. — Front at vertex rather broad, 0.37 of head width in two 

 specimens, widening almost immediately. Parafrontals gray pollinose 



