Q/XaJ^^j<UaA^ 



A SI LI D^.. 5o 



'.). Anterior intercalary vein continuous or nearly so with the fourth vein, 

 the last section of the latter oblique, closing or much narrowing the 

 broad first posterior cell. . . . Microstylum Macquart. 



Last section of the fourth vein continuous with the preceding section, 

 the first posterior cell not closed or narrowed (Central and South 

 America) Archilestris (Schiiier) Loew. 



10. Abdomen cylindrical, not narrow at the tip, elongate ; near the proxi- 



mal margin of the second and third segments with a white-pollinose, 



emarginate cross-band ; wings dark. . . Dizonias Loew. 



Abdomen less elongate, with five or si.x white-pollinose (interrupted or 



entire) cross-bands. . . . . . . . . .11 



11. Scutellum with bristles; veins at the outer ends of the discal and 



fourth posterior cells parallel. . < titTHO - k-EruoMviA -WTtitytnTn 

 Scutellum without bristles ; veins at the outer ends of the discal and pCw^- 



fourth posterior cells not parallel 12 



12. First posterior cell open, scarcely narroweil; face broad. 



Laphystia Loew. 

 First posterior cell closed or much narrowed. . Triclis Schiner. 



13. Antennae elongate, composed of five joints; nearly bare species. 14 

 Antcnnffi less elongate or short, composed of three joints with or with- 

 out a short or slender style. ....... 15 



14. First and second joints of the antenna? of nearly equal length, the third 



elongate, the fourth short, fifth elongate and densely pubescent ; 

 third and fourth not lobed at tij). . CERAXURfiTis Wiedemann. 

 First joint about three times the length of the second, third elongate, 

 the fourth and fifth of nearly equal length; third and fourth joints 

 at tlie tip with two lobes or processes, reaching to about the middle 

 of the following joint Myelaphus Bigot. 



15. Style of antenn;? short, thick, obtuse, not easily distinguisliable from 



the third joint, or if so forming apparent joints; antenna' nujre or 

 less elongate. .......... l^i 



Terminal style small, more slender than the joint, apparent ; anteniue 

 shorter. . . . . . . . . . . IH 



1(5 Nearly bare species; face flattened, bare, except below. Small or 

 rather small species, shining or metallic lilack, with narrow or cylin- 

 drical abdomen and large wings. . . . . . .17 



Thickly pilose species, the bristles few and hair-like; antenna> si)ring- 

 ing from a convexity, the facial profile thence receding to the facial 

 tubercle, which is situated ui)on the lower part of the face; abdo- 

 men short ; head narrow. .... Dk <h,<>m:s Loew. 



