38 PROCEEDINGS OF THE NATIONAL MUSEUM vol. io« 



Thoracic appendages: Front and middle legs completely yellow. 

 Hind legs: Coxae and femora yellow; tibiae yellowish brown; tarsi 

 very slightly blackened from fourth segment, remaining segments 

 yellow. 



Wing (fig. 8,d) length 2.3 mm., width 0.9 mm. Bands light brown. 

 Base of wing completely hyaline. First and second bands sub- 

 parallel, slightly oblique to costal margin, joined at costal margin; 

 sections of both bands in discal cell dislocated distally. Third band 

 appears perpendicular to costal margin. Fourth band consists of 

 large spot at apex of third vein. Section of fourth vein proximad of 

 anterior crossvein with verj^ slight bend. The part of fu-st basal cell 

 contiguous to second basal cell very faintly banded. Second basal 

 cell banded at apex. Halteres brownish yellow. 



Abdomen: Tergites dull, smooth, black. Disc of fh'st tergite with 

 pale setae. Genitalia (fig. 8,f,g) with apical part of aedeagus con- 

 sisting of a slender base with two long, filamentous, randomly twisted, 

 terminal tubes and an apparently'' colorless, elongated, membranous, 

 vesicalike structure attached to the base of apical part. 



Females: Body length 3.1-3.7 mm.; wing length 2.2-3.2 mm.; 

 frons yellowish broAvn or reddish brown; ovipositor sheath dark bro^vn. 

 Otherwise similar to the male. 



Specimens examined: Arizona (399, Icf): Huachuca Mts. 

 (Sunnyside Canyon), Ruby; July 13. New Mexico (19): Silver 

 City; July 22. 



Remarks: This species is easily distinguished from other Rivellia 

 by the banding of the wings, the presence of a prominent seta ventral 

 to the subalar, a broad pruinose band on the pleuron which extends 

 from the ventral corner of the sternopleuron to the dorsal margin of 

 the mesopleuron, and the male genitalia. 



The presence of the elongated, membranous vesica on the apical 

 part of the aedeagus is unique in this species. The location of the 

 gonopore is uncertain. In view of the randomly twisted terminal 

 tubes, it is suggested that the gonopore is located on the vesica. 



Rivellia metallica (Van Der Wulp) 



Figure 4,e-A 



Herina metallica Van Der Wulp, 18G7, p. 154, pi. 5, fig. 10. 



Rivellia metallica (Van Der Wulp) Hendel, 1914a, p. 178, pi. 2, fig. 34; 1914b, 

 pi. 2, fig. 34.— Cresson, 1924, p. 229. 



Type locality: Unknown. 



Males: Body length 2.7-4.2 mm. 



Head: Frons reddish brown or dark brown; upper fronto-orbital 

 plates and ocellar triangle, blackened. Face with dorsal half pruinose, 

 ventral half shining, smooth, dark brown or black medio ventrally 



