NORTH AMEUICAN DIPTERA. 91 



Spogodylum Macq., a South American genus, and Thlipsogaster 

 Rond., are now for the first time recorded from North America. 



Three new genera are described in the present paper : Aldrichia, 

 near Ecllmm, but with three submarginal cells and the second and 

 third veins forking near the small cross-vein ; Exepacmus, near 

 Epaanus, but with three submarginal cells and a different antennae; 

 and Gemiaaria, near Lordotiis, but having the scutellum dec])ly 

 sulcate longitudinally. 



Genera of Bombylidse from America North of Mexico. 



Second and third veins forking at or near the small cross-vein, the distance being 



never greater than the length of that cross-vein 1. 



Second and third veins forking far before the small cross-vein and usually before 



the base of the discal cell 9. 



1. — Third antennal joint bisected by a suture, forming a distinct lermiual 



style 2. 



Third antennal joint never bisected by a suture, the style when present 



indistinct 7. 



2. — Pulvilli spine-like, indistinct; anterior branch of third vein connected with 



the second by a cross- vein 3. 



Pulvilli pad -like, distinct 5. 



3. — Anterior branch of third vein near its middle connected with the third by 



a cross-vein Hyperaloiiia. 



Anterior branch never connected with the third vein by a cross-vein 4. 



4. — First posterior cell near its middle bisected by a cross-vein.. ..E.voptsila. 



First posterior cell never bisected by a cross-vein. ExoproM<»|»:i. 



5. — Second antennal joint less than one-half as long as the third, the style 



bearing numerous hairs 6. 



Second antennal joint as long as the third, the style destitute of hairs. 



Aldrichia n. gen. 

 6. — Anterior branch of third vein near its middle connected witli the third 



vein by a cross-vein Spo$;o!$tyiliiii. 



Anterior branch never connected with the third vein by a cross-vein. 



Argyrainceba. 

 7. — Anal cell widest near its middle, its apex less than half as wide as the 



length of the axillary cell 8. 



Anal cell widest at its apex, where its width equals one-half the length of 



the axillary cell 9Iaiicia. 



8. — Penultimate section of fifth vein at least two-thirds as long as the ultimate 

 section, sides of abdomen furnished with long scales, front tibia; bristly. 



liepidaiitlirax. 



Penultimate section of fifth vein less tlian two-thirds as long as the ultimate 



section Anthrax. 



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



