FLIES OF GENUS RIVELLIA — NAMBA 67 



remainder shining, slightly rugulose, brown; parafacials and part of 

 orbits ventral to each eye yellow. Antenna somewhat cylindrical in 

 general appearance, little tapered toward rounded tip; first and 

 second segments yellow; third segment with tip and outside slightly 

 blackened, remainder yellow. Anteclypeus concolorous with ventral 

 portion of face. Palpi yellow. Postcranium strongly convex; shining 

 black, not pruinose. Head directed anteriorly instead of ventrally 

 as is the case in other Rivellia. 



Thorax: Mesonotum black; strong humeral and posterior dorso- 

 central setae absent, relatively strong anterior dorsocentral setae 

 present. Scutellum and postscutellum concolorous with mesonotum; 

 lateral pair of scutcllar setae very weak, about one-fifth the length of 

 apical pair; shining area on postscutellum confined to medioposterior 

 spot. Pleura dark brown. Mesopleuron with scattered pale setae 

 on posterior two-thirds; posterior two-thirds pruinose. Sterno- 

 pleuron almost wholly pruinose, only anterior and posterior corners 

 shining; disc mth scattered pale setae. Disc of pteropleuron with 

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

 Hypopleuron with shining central spot, remainder pruinose. Latero- 

 tergite completely and densely pruinose. Prosternum black. 



Thoracic appendages : All legs \\ath coxae and femora yellow. Front 

 and middle tibiae yellow; hind tibiae brownish yellow. Fore tarsi 

 and middle tarsi slightly blackened from second segment, remaining 

 segments yellow; liind tarsi blackened from fourth segment, remaining 

 segments yellow. 



Wing (fig. 2,a) length 4.3 mm., width 1.6 mm. Bands dark brown, 

 narrow. First and second bands definitely joined at costal margin; 

 thu-d and fourth bands joined at costal margin. The part of first 

 basal cell contiguous to second basal cell banded at base anteriorly; 

 the hyaline area contiguous to fourtli vein sharply wedgelike to base 

 of second basal cell. Section of fom-th vein proximad of anterior 

 crossvein with very slight bend. Halteres yellowish brown. 



Abdomen: Tergites black, definitely pruinose except for shining 

 medial transverse band on first-second syntergite, this band broadened 

 laterally. Disc of fii'st tergite with pale setae. Genitalia (fig. 2,c) 

 with apical part of the aedeagus consisting of two stout apically 

 directed hooks which are joined at base. 



Females: Body length 6.2-7.5 mm.; wing length 4.0-4.6 mm. 

 Prosternum yellow; abdomen with yellow lateral spot on each side at 

 base on dorsum; ovipositor sheath black. Otherwise similar to male. 



Specimens examined: Florida: Jacksonville (1 9, collection of 

 Mrs. A. T. Slosson) ; Suwanee Springs (1 9,10?", July 29, 1939, R. H. 

 Beamer). Georgia: Perry (1 9, Aug. 12, 1939, R. H. Beamer). 

 North Carolina: Fayetteville (1 9, early June, 1921, C. S. Brimley). 



