180 U.S. NATIONAL MUSEUM BULLETIN 2 77 



the midline. Pleural areas of prothorax cream, mesanepisternum 

 yellow with a red-brown patch; mesokatepisternum red-brown with 

 a yellow band above, all covered with granular pollen. Wings smoky, 

 veins tan ; halter stem brown, knob cream ; legs yellow-brown, becoming 

 brown distally. 



Abdomen second segment with red-brown "T" with white lateral 

 and posterior margins, remaining segments with red-brown "T"s 

 fading posteriorly, mostly white; nmth tergum with red-brown basal 

 spot, remainder white, with long hairs; see figure for details. 



Female.^ — -Head cream; eyes red-brown to metallic, with a broad 

 postocular band extending across back of head, brown patches from 

 corner of eyes to back of head; frons broad, with a median groove 

 bordered by two bands occupying a little more than half of the 

 frontal width, separated from postocular ridge by a shallow sulcus 

 from the corner of the eye to the back of lateral ocelli, ocellar triangle 

 red-brown, pollinose; ocelli orange to red. Antennae (missing on 

 allotype) first two segments brown, third orange. See figure for shape. 



Thorax dorsum with red-brown median and lateral stripes as in 

 male, separated by orange stripes, lateral margins yellow-orange, 

 all covered by gray pollen; humeral and supra-alar caUi cream; 

 scutellum yellow, with a median stripe. Pleural areas as in male. 

 Wings smoky brown, veins tan; halter stem cream, knob cream. 

 Legs as in male. 



Abdomen with median red-brown "Ts," which become fainter pos- 

 teriorly; lateral and posterior areas tan. Eighth segment red-brown; 

 ninth tergum with 6 stiff spines and much hair; see figure for details. 



Length : Male body 2.7 mm., wing 2 mm. ; female body 4 mm., wing 

 2.1 mm. 



Type-locality : Los Angeles, California (Coquillett) as paratype of 

 Pseudatrichia griseola. 



Holotype: Male (USNM) 67483. 



Allotype: Female on same pin. 



Paratypes: 1 d^, Corcoran, California, 22 July 1947 (W. W. Wirth) ; 

 2 cf cf , West Side Sta., California, 25 April 1930, on L. alyssoides; 1 9, 

 Victorville, California, 30 May 1944 (A. L. Melander) (USNM). 



126. Brevitrichia davisi, new species 



Figure 120 



Male. — Head cream; eyes red-brown above with blue-green metal- 

 lic luster, lower half more intensely green; frons narrow, triangular; 

 ocellar tubercle red-brown, frosted with gray pollen, ocelli orange. 

 Antennae with first two segments tan, third segment lost. 



Thorax dorsum with black-brown mid-dorsal band, flanked by two 

 lateral bands, area above humeral callus tan, lateral margins and 



