566 LIST OF DIPTEEA. 



Genus 11. ATOMOSIA. 



Corpus sfepissime punclatum. Caput mystace conspicuo. 

 Proboscis porrecta. Antennae triarticulatae, non stylatce, insertione 

 solita ; articulus 3us nudus, obtusus. Oviductus brevis. Alarum 

 vena3 cubitalis furca antica simplex ; vena? transversa? posteriores 

 lineam unam omnino aut fere fingentes. 



Atomosia, Macq. Dipt. Exot. i. 2, 73. 

 Laphria, p., Wied. 



Fore fork of the cubital vein undulating, much curved near the 

 base ; hind fork more or less curved, inclined towards the first 

 externo-medial vein, but at some distance from it on the border; 

 second externo-medial straight ; third forming a right angle with 

 the praebrachial, in a line with the discal areolet, joining the fourth 

 at a long distance from the border. Subanal joining the anal very 

 near the border. 



North America. 



A. Pedes nigri, tibiis testaceis. - pusilla, Macq. 



B. Pedes pallidi. 



A. Abdomen rufo marginatum. ... macrocera, Say. 



B. Abdomen non marginatum. - rufipes, Macq. 



1. Atomosia pusilla. 

 Viridi-nigra ; tibia testacea ; alee subhyalina. 

 Atomosia pusilla, Macq. Dipt. Exot. i. 2, 76, 6. 

 North America. 



2. Atomosia macrocera. 



Foem. Nigra, niveo pubescens ; abdomen rubro marginatum ; 

 pedes rubri ; aim cinerece. 



Laphria macrocera, Say, Journ. Acad. Philad. iii. 73, 3. Wied. 

 Auss. Zweifi. i. 531, 57. 



Pennsylvania. 



3. Atomosia rufipes. 



Foem. Nigra; abdominis incisurm alb(e ; pedes fulvi, tibiis pos- 

 ticis upice nigris ; alee basi subjlavescentes. 



Atomosia rufipes, Macq. Dipt. Exot. i. 2, 39, 9. 



Philadelphia. 



