204 U.S. NATIONAL MUSEUM BULLETIN 277 



Female. — Unknown. 



Length: Male body 4.3 mm., wing 2.5 mm. 



Type-locality: Isla Ildefonso, Gulf of Calif., Mexico; 30 March 

 1953 (P. H. Arnaud). 

 Holotype: Male (CAS) 8931. 



140. Brevitrichia ordwayi, new species 



Figure 134 



Male. — Head cream; eyes black-brown above, darker below; frons 

 triangular, with a small tan triangle on the lower frontal area above 

 the antennae; ocellar tubercle black-brown, dusted gray pollen, ocelli 

 black-brown. Antenna with first segment red-brown; second segment 

 black-brown; third segment reddish-brown, covered with short golden 

 hairs. See figure for details. 



Thorax dorsum black-brown, poUinose; a small yellow patch above 

 humeral callus; lateral margins yellow, two short bands of yellow 

 extending anteriorly from the lateral angles of scutellum; humeral 

 callus buff, with a red-brown patch above; scutellum with a large 

 red-brown patch medially, yellow on lateral angles. Prothorax yellow, 

 mesanepisternum yellow, with a red-brown patch, mesokatepisternum 

 red-brown, with a dorsal yellow band; wings hyaline, veins brown 

 anteriorly tan posteriorly; halter stem brown, knob tan. Legs black- 

 brown pollinose, knee of femur yellow. 



Abdomen segments dark brown with light posterior margins; 

 ninth tergum tan, with a black-brown patch basaUy; see figure for 

 details. 



Female. — Head cream; eyes red-brown, metallic; postocular 

 ridges medium wide with red-brown median patches, the two sides 

 widely separated; frons tan, with a median groove bordered by a 

 brown band that narrows toward the ocellar tubercle; ocellar tubercle 

 red-brown, pollinose, ocelli red; a groove extending from the corner 

 of each eye cutting off a central piece as wide as the ocellar tubercle. 

 Antennae with first two segments brown, third segment orange- 

 brown; see figure for details of head. 



Thorax dorsum red-brown, heavily covered with gray pollen, 

 spot above humeral callus yellow, lateral margins narrowly yellow 

 between humeral and supra-alar calli, orange stripes extending 

 anteriorly one-third the length of the dorsum from the scutellar 

 groove, bordering a central stripe of red-brown; humeral and supra- 

 alar calli cream; scutellum yellow, with a median band of red-brown. 

 Prothorax cream, mesanepisternum cream, with a central red-brown 

 patch, mesokatepisternum red-brown, with a dorsal yellow stripe. 



