PROCEEDINGS OF THE NATIONAL MUSEUM vol.70 



G^ Thorax and abdomen without bands of tomentiim (Dolio- 



syrpTius) Eristalis Latreille. 



F'. Marginal cell open. 



G\ Densely pilose, bumblebee like in appearance Mallota Meigen. 



G^ Not deni?ely pilose, unlike bumblebees in appearance. 



H\ Ocelli widely spaced ; frontal lunule very large and broad ; 

 head much broader than high ; males widely dichopt ic. 



Dolicho^na Macquart. 

 H^ Head, ocelli, and frontal lunule normal ; males holoptic 

 (always?). 

 I\ Third antennal joint much longer than broad ; first tergite 



with dense, appressed, yellow pile Quichiiana Knab. 



r. Third joint subquadrate. 



J\ Head broader than thorax ; mesouotum without light 



stripes Habromyia Wiliiston. 



Jl Head not broader than thorax ; niesonotuni ^^•ith light 



longitudinal stripes Helophilus Meig-en. 



^ Third vein straight or moderately curved downwards ; facial slopes 



usually bare (pilose in some Chilosinae). 

 F'. Discal cross vein joining discal cell well before its middle ; meta- 



sternum bare chilosinak. 



G\ Apical cross vein (post angular section) directed obliquely 

 inward ; mesosotum distinctly broader than long. 



Alipumilio, new genus. 

 G^ Apical cross vein not directed inward ; mesouotum longer than 

 broad. 

 H'. Body deeply pitted ; length of arista equal to width of third 



antennal joint Nausigaster Will iston. 



H^ Body not noticeably pitted ; arista longer than width of third 

 joint. 

 I*. Face distinctly pilose. 



J\ Arista longer than antenna, discal cross vein directed 



outward {Pipiza) Penium Philippi. 



J^ Arista much shorter than antenna ; discal cross vein 

 (post angular section) dii*ected upwards, then out- 

 wards on distal half Halictomyia, new genus. 



I^ Face bare. 



J\ Frons and face rugose, apical cross vein upright. 



Chrysogaster Wiliiston. 

 J^ Frons and face not rugose ; apical cross vein directed 

 outward. 

 K'. Body pile modified, scalelike ; metasternum mem- 

 branous behind. 

 L*. Antenna moderate, second and third joints as long 



as broad Eumyiolepta Shannon. 



L-. Antenna much elongated, second and third joints 



much longer than broad lepidostola Mik. 



K'. Body pile normal, composed of flue hairs ; meta- 

 sternum girdled with chitin. 

 I}. Face with a straight keel ; a transA^erse row of small 

 black spines on anterior margin of mesouotum ; 

 male holoptic Zonemyia Shannon. 



