﻿1927] Curran, Diptera of the Belqian Congo 35 



Prothorax not strongly developed, without long bristles 3. 



3. Metasternum strongly developed, so that the coxae are all approximate; al)- 



domen long and slender, enlarged apically; antennae very long. 



Systropus Wiedemann. 



Metasternum short, the legs not unusually approximate at Ijase; abdomen 



robust; antennae not as long as head and thorax 4. 



4. First posterior cell broadly open; metapleura hairy or l)are. .Djschi.'^tus Loew. 

 First posterior cell closed; metapleura usually hairy 5. 



5. Posterior border of the eyes with a deep emarginatioii opposite the antenme; 



first posterior cell closed by the fourth longitudinal vein. 



Eurycarenus Loew. 



Posterior border of the eyes but little or not at all sinuate; first posterior cell 



closed by the third longitudinal vein 6. 



6. First basal cell longer than the second Bombylius Linné. 



First basal cell not or scarcely longer than the second Systoechua Loew. 



7. Second longitudinal vein originating well before the anterior crossvein, usually 



arising at an angle 8. 



Second vein originating opposite or nearly opposite the anterior crossvein at 

 right angle or nearly so 9. 



8. Anterior crossvein situated very much beyond the middle of the discal cell. 



Antonia Loew. 

 Anterior crossvein situated at most slightly beyond the middle of the discal cell. 



Petrorossia Bezzi. 



9. Metapleura bare; styliform part of third antennal segment bisected at base and 



with an apical pencil of hairs 10. 



Metapleura pilose; third antennal joint not as above 11. 



10. Third antennal segment broader than the second, not inserted in the second seg- 



ment Anthrax, Scopoli. 



Third antennal segment globular, inserted in the cup-shaped second segment. 



Spogostylum Macquart. 



11. Front tibiae with more or less regularly arranged tiny spicules Villa Lioy. 



Front tibiae smooth, without spicules ThyndaiUhrax Osten Sacken. 



Bombylius Linnaeus 

 The species recognized may be distinguished by the following table. 



1. Second longitudinal vein straight or almost so; anterior crossvein beyond middle 



of discal cell analis Fabricius. 



Second longitudinal vein undulating; anterior crossvein situated before the 

 middle of the discal cell 2. 



2. Black pattern at the base of the wings extended to the discal crossvein; third 



antennal segment long and deeply concave at apex .... argentatus Fabricius. 

 Black pattern at base of wing not extending beyond the basal cross veins 3. 



3. Abdomen mainly clothed with yellowish hair* auricomus Bezzi. 



Abdomen black-haired, the dorsum with abundant golden tomentum. 



rufiventris Macquart. 



