NOR ill AMKRICAN DIPTKRA. Ill 



1. — Last section of tliird vein as long as the preceding section 4. 



Last section of tliird vein never more than two-thirds as long as the preced- 

 ing section, third antennal joint narrow and tapering to the tip, palpi 



never reaching heyond epistonia 2. 



2. — Femora largely or wholly hlack 3. 



Femora yellow, front of female yellow tomeniose in the middle. 



? rufipeN Macq. 

 3. — Front of female wholly white tomentose, small cross-vein distinctly beyond 



middle of discal cell senilis Fahr. 



Front of female yellow tomentose in the middle, small cross-vein in middle 



of discal cell siibauralus Loew. 



4. — Abdomen slender, ni-arly four times as long as wide, paljji never projecting 



beyond epistonia 5. 



Abdomen robust, never more than twice as long as wide, third antennal joint 



never sharp pointed G. 



o. — Femora and base of venter largely yellow caivtis Loew. 



Femora and venter wholly black Iiybus n. sp. 



6. — Abdomen opaque 7. 



Abdomen shining black, the segments margined behind with yellow. 



ciuctiira n. sp. 



7. — Abdominal segments never bordered posteriorly with yellow 8. 



Abdominal segments bordered posteriorly with yellow Taseiola Coq. 



8. — Palpi less than one-fourth as long as the proboscis trocliiliis n. sp. 



Palpi more than one-half as long as the proboscis capax Coq. 



Oeroii troeltiliis n. sp. % J. — Opaque, black, only the halteres yellowish 

 white. Head and body gray pollinose, a short vitta in front of ocelli in the 

 female, four stripes on the thorax, extreme base of scutellum greatly expanded 

 backward in tlyj middle, ami extreme base of each abdominal segment, opaque 

 black ; pile of head and body, and of all their members, whitish. First antennal 

 joint slightly over twice as long as the second, the third joint more than twice 

 as long as the first, of nearly an equal width, slightly widest just before the 

 middle, the apex rounded, except at the upper angle, which is cut away, the 

 portion thus cut out nearly equaling one-third the width of the joint; on upper- 

 side of third joint near its base are four or five stout bristles, which are about 

 one-fourth as long as the width of this joint; bristles on upperside of first joint 

 (there are none on the underside) shorter than the width of this joint. Pro- 

 boscis as long as the head and thorax united. Wings hyaline, apex of subcostal 

 cell yellowish, last two sections of third vein subcqual in length, apex of second 

 submarginal cell less than half the length of that cell, posterior cross-vein 

 strongly bowed outwardly. Length 3-5 mm. 



Southern Calitbrniii. One male and two females, in April. 



Gcroii ciiictiira n. sp. 9 ■ — Same as trochilus, with these exceptions: Apex 

 of each abdominal segment, both dorsally and ventrally, except the first one, 

 yellowish white. Body shining, except the pleura, scutellum, three stripes in 

 middle of thorax and its lateral margins, which are lightly gray pollinose ; third 

 antennal joint one and a half times as long as the first, destitute of bristles, first 

 joint with bristles on both its upper and lower sides, many of these being three 

 times as long as the width of this joint. 



TRANS. AM. ENT. SOC. XXI. MARCH, 1894. 



