172 U.S. NATIONAL MUSEUM BULLETIN 2 77 



frons broad a little wider than the ocellar triangle, with a median 

 groove running the entire length, a brown central band clothed with 

 a few sparse hairs, grooves from upper angle of eye extending to 

 back of head laterad of the midline. Ocellar tubercle red-brown, 

 with tan pollinose scales, ocelli orange. Antennal segments brown, 

 shaped as in figure. 



Thorax dorsum red-brown ground, covered with longitudinal 

 red-brown pollinose bands; humeral and supra-alar calli orange to 

 cream, with a light area between. Pleural areas as in male; wings as 

 in male; legs as in male; halter cream. 



Abdomen segments brown, with light membranous margins; 

 eighth segment orange-brown, ninth tergum with 8 stiff spines 

 sparse hairs, 10th tergum with a thick pencil of long hairs at base. 



Length: Male body 2.5 mm., wing 1.8 mm.; female body 4 mm., 

 wing 2.3 mm. 



Type-locality: Los Frailes, Baja California, Mexico; 18 March 

 1953 (P. H. Arnaud) Sefton Orca Exped. to Gulf of California. 



Holotype: Male (CAS) 8930. 



Allotype: Female on same pin, sama data. 



Paratypes: 1 cT, Cabo San Lucas, Baja California, Mexico, 

 16 March 1953 (P. H. Arnaud); 2 9 9, Los Frailes, Baja California, 

 Mexico, 18 March 1953 (P. H. Arnaud) (CAS). 



121. Brevitrichia aspinosa, new species 



Figure 115 



Female.^ — Head cream; eyes red-brown, probably metallic in 

 life; postocular ridge moderately wide, continuous behind ocellar 

 triangle, with a wide brown spot behind each eye; frons broad, with 

 a median groove bordered by bands of tan; sparse hairs over entire 

 frons; ocellar triangle red-brown, ocelli clear; grooves from upper 

 corner of eyes extending to lateral ocelli. Antennae with first two 

 segments brown; third segment orange-brown basally darkening to 

 brown distally; see figure. 



Thorax tergum red-brown with lateral margins yellow, two yellow 

 streaks laterad of brown midline stripe posteriorly, all covered with 

 gray pollen; humeral and supra-alar calli yellow. Scutellum tan, 

 with a brown spot occupying the middle third. Pleura with prothorax 

 red-brown and cream, mesanepisternum cream with large red areas, 

 katepisternum red-brown with cream dorsal stripe, pollinose. Wings 

 smoky, veins brown; halter stem tan, knob yellow-brown. Legs with 

 femora red-brown, pollinose; knees yellow, tibiae and tarsi brown. 



Abdomen red-brown with white membranous posterior margins. 

 Eighth segment red-brown, ninth tergite with no spines but 8 pits; 

 see figure. 



