176 Friedrich Hendel. 



reaching- to near the oral margin. Proboscis black, thick. Thorax, scutellum 

 and abdomen black, covered with short greyish liairs; the abdomen ovate, 

 posteriorly pointed; 2. Joint of the ovipositor pale rufous. Legs piceoiis, 

 somewhat dark rufous, the tarsi clearer. Wings hyaline; the 1. cross-band 

 much broader than the others, connected with the blackish base, the 

 Separation being only indieated by one or 2 small, elongate, hyaline Spots; 

 the 2. cross-band united with the 1. just before the small cross-vein, the 

 2 prolonged together in a less intense infuscation in the middle of the 

 discal cell; the 3. cross-band united with the 4. and with it forming a 

 narrow border round the tip of the wing." 



4G. Jiivellla Widplana n, sp. 



BivcIUa conjuncia \':ui der Wulp, Biol. Centr. Amer. Dipt., Vol. 2, p. 283, 

 Taf. 10, Fig. 11 (1898). — Cresson, Trans. Amer. Ent. Soc., A^ol. 32, p. 279 (1906). 



1 9 aus Mexiko, Orizaba (leg. Crawford), Samml. Prof. Bezzi. 



Von RiveUia conjuncta Loew durch folgendes gut unterscheidbar: 

 Die dunkelrote Stirnstrieme ist zwischen den schmalen weißen Augen- 

 randsäumen fast quadratisch, wenig länger als breit, bei conjuncta 

 doppelt so lang wie breit, weil die Augenrandsäume viel breiter sind. — 

 Der Hinterleib ist gelblich, an der Wurzel sogar weißlich behaart; bei 

 confimcta sind die Härchen schwarz und schimmern dunkelrot. — Die 

 Unterschiede in der Flügelzeichnung habe ich schon in der Tabelle er- 

 wähnt. 



47. Jtivellia conjuncta Loew. 



Monogr. N.-Amer. Dipt., Vol. 3, p. 88, 1, PL 8, Fig. 3 (1873). 



Ich kenne diese Art vorläufig nur aus den Vereinigten Staaten und 

 glaube, daß die aus Mexiko und Zentralamerika erwähnten Stücke alle 

 der B. Widplana angehören. Man vergleiche das dort Gesagte. 



48. liiveUia connecta V. d. Wulp. 



Biolog. Centr. Amer. Dipt., Vol. 2, p. 383, 5, Tab. X, Fig. 12 (1899). 



1 cf, Mexico, Chipancingo in Guerrero, 4600 feet. 



„Shining black; front and antennae brownish; legs black, the base 

 of the tarsi yellowish; the second cross-band in the middle largely 

 united with the first, which is connected with the blackish base. — • Length 

 2ü mm. — Front brownish, as broad as the eyes, with parallel sides; face 

 cinereous, perpendicular, not excavated; clypeus large; occiput black; 

 Antennae rufous; the 3. Joint on the forside and towards the tip infus- 

 cated; arista pale rufous. Thorax, scutellum and abdomen shining black; 

 the abdomen ovate. Legs black; the tarsi yellowish, but infuscated to- 

 wards the tip. Halteres blackish. Wings hyaline; the first cross-band is 

 broad and at the Costa largely connected with the blackish base — in 



