28 PROCEEDINGS OF THE NATIONAL MUSEUM vol. im 



joins second band. Second band separated from first band at costal 

 margin, joined distinctly to third band in discal cell. Third and fourth 

 bands narrowly joined at costal margin. Small whitish spot present 

 on fourth vein just proximad of apex of second basal cell. Section of 

 fourth vein proximad of anterior crossvein with deep bend. Halteres 

 yellow toward base, remainder brownish. 



Abdomen: Tergites shining, smooth; first two tergites and part of 

 third yellow, remaining segments dark brown. Disc of first tergite 

 with pale setae. Ovipositor sheath brownish j^ellow or brown. 



Specimens examined: Florida: 299, Drayton Island, May 7-9. 



Remarks: The wing banding of this species distinguishes it from 

 the other Rivellia. 



Rivellia coquilletti Hendel 



Figure l,g-j 



Rivellia hasilaris Coquillett, 1900, p. 21 (not Trypeta basilaris Wiedemann, 



1830).— Cresson, 1924, p. 225. 

 Rivellia coquilletti Hendel, 1914a, p. 180, pi. 1, fig. 26; 1914b, pi. 2, fig. 26. 



Lectotype: I hereby select as lectotype a male specimen bearing 

 the labels "Type No. 4469, USNM," "Col.," "Pdvellia coquilletti 

 Hend.," and "Rivellia basilaris Coq." 



Type locality: Southern Colorado. 



Males: Body length 3.7-5.0 mm. 



Head: Frons yellowish brown; upper fronto-orbital plates and 

 ocellar triangle black. Face with dorsal two-thirds pruinose, ventral 

 one-third shining, of milky light gray color; parafacials and part of 

 orbits ventral to each eye brownish yellow. Antenna with first and 

 second segments brownish yellow; thu'd segment with tip and outside 

 blackened, remainder yellow, the tip pointed anteriorly. Anteclypeus 

 dark bro^vn or black. Palpi yellow. Postcranium dark brown or 

 blackish green, pruinose. 



Thorax: Mesonotum dark brown or blackish green; strong humeral 

 and posterior dorsocentral setae present. Scutellum and post- 

 scutellum concolorous with mesonotum. Pleura dark brown or 

 blackish green, mostly shining. Mesopleuron with scattered pale 

 setae on posterior half; pruinose area at dorsal posterior corner in 

 form of a marginal strip which extends from midpoint between 

 anterior spiracle and dorsal posterior corner to dorsal posterior corner, 

 then ventral to a point slightly past midpoint between dorsal posterior 

 and ventral posterior corners. Sternopleuron with ventral corner 

 and a ver}^ narrow strip on posterior margin pruinose; disc with 

 scattered pale setae. Disc of pteropleuron with scattered pale setae, 

 black setae present or absent ventral to subalar. Hypopleuron with 



