Die Arten der Platystominen. 1 '^ 



Thorax, scutellum nnd abclomen shining- black: sciitellum with 2 long 

 bristles; abclomen elleptical. Legs black, the tarsi, save the last 2 or 3 

 joints, yellowish rnfous; tlic femora somewliat elongate; the hind tibiae 

 slightly curved. Halteres brown. Wings hyaline, with a blackish pattern: 

 the 1. cross-band broad, completely imited with the blackish base, on the 

 outer side convex, inferiorly reaching to beyond the 5. vein; the other 

 cross-bands narrower; the 2. issuing from the costa at the termination of 

 the 1. vein, and in an ()l)liqne direction reaching the small cross-vein, 

 where it is angulary curved and goes more perpendiculary to 

 the hind margin of the wing; the 3. cross-band straight, at the hind mar- 

 gin connected Avith the 2. and at the costa with the fourth, which borders 

 the tip of the wing." 



44. mvellia subtnetalllca V. d. Wulp. 



Biol. Centr. Americ. Dipt., Vol. 2, p. 382, 3, Tab. X, Fig. 10 (1899). 



1 o", Mexico, Omilteme in Guerrero, 8000 feet. 



„Black, slightly metallic; front and legs rufous; tibiae brown; the 

 tirst cross-band angular. — Length 4 mm. — Front dark rufous, a littlc 

 broader than the eyes, with parallel sides; face distinctly excavated, 

 greyish; the clypeus and the cheeks pale rufous; inferior portion of the 

 cheeks larger than in the other species of the genus; occipud black. Basal 

 joints of the antennae rufous (the 3. Joint is wanting). Thorax and scu- 

 tellum black; thoracic dorsum with a short, dense, yellowish pilosity: 

 pleurae with some bluish metallic reflections; scutellum with 2 bristles. 

 Abdomen curved downward, rather broad at the base, attenuated towards 

 the tip, somewhat metallic greenish-black, densely covered by a greyish 

 pilosity; genitalia on the ventral side with 2 appendages. Fore coxae 

 yellowish-rufous, middle and hind coxae black; legs yellowish-rufous, the 

 tibiae and the terminal 2 or 3 tarsal joints brown. Halter blackish. Wings 

 greyish-hyaline; the brown pattern generally agreeing with that of 

 U. micans Loew, but the first cross-band is angular in shape, distinctly 

 separated from the blackish base and, though less intense, prolonged to 

 beyond the 5. vein." 



45. Bivellia pilosula V. d. Wulp. 



Biol. Centr. Americ. Dipt., Vol. 2, p. 384, 1, Tab. X, Fig. 14 (1899). 



1 9, Mexico, Teapa in Tabasco. 



„Blackish, with grey pilosity; 1. cross-band broad, connected with 

 the blackish base of the wing and inferiorly with the much narrower 

 2. cross-band, the 3. and 4. bands united at the costa.— Length 25 mm.— 

 Front brownish-rufous, as broad as the eyes, with parallel sides; face 

 greyish, very slightly excavated; inner orbits of the eyes white. Antennae 

 rufous; the 3. Joint more obscur, somewhat pointed towards the tip, 



