70 PROCEEDINGS OF THE NATIONAL MUSEUM vol. loe 



pleuron with scattered pale and black setae on posterior half; sterno- 

 pleuron with scattered pale and black setae on disc; pteropleuron with 

 scattered pale setae, few black setae present ventral to subalar. 

 Laterotergite completely pruinose. Prosternum yellow. 



Thoracic appendages: Front and middle legs: Coxae, femora, 

 and tibiae completely yellow; tarsi very slightly blackened from 

 third segment, remaining segments j^ellow. Hind legs: Coxae and 

 femora yellow; tibiae light brownish yellow; tarsi blackened from 

 third segment, remaining segments yellow. 



Wing (fig. l,a) length 3.7 and 4.0 mm., width 1.7 mm. Bands 

 hght brown, broad. First band covers most of the base of the wing 

 although faintly in the axillary lobe and anal and axillary cells. 

 Second band joined faintly to fu-st band at costal margin, joined 

 distinctly to third band in discal cell. Third and fourth bands broadly 

 joined at costal margin. Section of fourth vein proximad of anterior 

 crossvein with deep bend. Halteres yellow, capitulum somewhat 

 brownish. 



Abdomen: Tergites shining yellow, slightly rugose, with scattered 

 brownish blotches. Disc of first tergite with pale setae. Genitalia 

 (fig. l,c) with apical part of aedeagus consisting of a slender neck, 

 bulbous head, and two long terminal tubes each bearing a horn at 

 basal one-third. 



Female: Body length 5.0 mm.; wing length 4.2 mm., width 2.0 

 mm.; ovipositor sheath brownish yellow, blackened laterally at tip. 

 Otherwise similar to holotype. 



Specimens examined: Florida: Hilliard (2cf cT, Aug. 19, 1930, 

 and 19, Aug. 31, 1930, R. H. Beamer). 



This species can be easily distinguished from the other Rivellia 

 by the wing banding, the absence of inner verticals and strong 

 humeral setae, the general yellowish color, and the male genitalia. 



Rivellia qiiadrifasciata (Macquart) 



Figure 6,a-c 



Herina quadrifasciata Macquart, 1835, p. 433. 



Rivellia quadrifasciata (Macquart). Loew, 1873, p. 90, pi. 8, fig. 5. — Hendel, 

 1914a, p. 180.— Cresson, 1924, p. 227. 



Type locality: North America. (The type "ties certainement 

 detruits," according to E. Seguy, in litt.) 



Males: Body length 3.6-6.4 mm.; wing length 3.0-4.0 mm. 

 Genitalia (fig. 6,6,c) with apical part of aedeagus from lateral view 

 consisting of a somewhat hemispherical base and two filamentous 

 terminal tubes which are subequal in length to basal part of aedeagus. 

 Fourth sternite of abdomen with radially directed setae. Otherwise 

 similar to R. colei. 



