260 U.S. NATIONAL MUSEUM BULLETIN 2 77 



174. Pseudatrichia nordeni, new species 



Figure 168 



Female. — Head black; eyes black-brown, postocular flange broad; 

 frons broader than ocellar triangle, swollen, with a long pit in front 

 of median ocellus, and with longitudinal striations that give it a dull 

 appearance; ocellar triangle flat, cut off; ocelli orange. Mouthparts 

 small, only half the length of the oral opening, palpi short. Antennae 

 with first two segments red-brown, third segment orange-brown, 

 tapering, forked at tip; see figure for details. 



Thorax dorsum black, transversely striated; humeral and supra- 

 alar calli brown-orange; pleura dark red-brown. Wings clear, veins 

 brown; halter stem brown, knob with base and dorsal half brown, 

 ventral half white. Legs w^th all coxae straw colored; front legs 

 yellow-brown, middle legs orange-brown, hind legs red-brown. 



Abdomen with segments 2-4 black, rugose, with a purple sheen; 

 segments 5-7 black, shining; eighth segment black, hairy, eighth 

 sternum three-pointed with the median point truncated; see figure 

 for details. 



Male. — Unknown. 



Length: Female body 6.5 mm., wing 4 mm. 



Type-locality: Norden, Nevada Co., California; 15 August 1951. 



Holotype: 9 (CAS) 8935. 



175. Pseudatrichia parva D. E. Hardy 



Figure 169 



Pseudatrichia parva D.E. Hardy, 1944a, p. 36. 



This species is known only from the female, which is figured. 

 Length: Female body 3.7 mm., wing 2.7 mm. 

 Type-locality: Flagstaff, Arizona; 8 July 1941 (R. H. Beamer). 

 Type: (UKan). 



176. Pseudatrichia parvipennis, new species 



Figure 170 



Male. — Head black, eyes red-brown above, darker below; post- 

 ocular ridge very narrow; frons short, swollen, extending one-third 

 the distance to the ocellar triangle; ocellar tubercle raised, ocelli red; 

 mouthparts red-brown, short, half the length of the oral opening, 

 palpi shorter. Antennae orange-brown, third segment truncated; see 

 figure for details. 



Thorax dorsum black, transversely striated ; humeral and supra-alar 

 calli deep red-brown; pleura deep red-brown. Wings brownish, veins 

 brown; halter stem brown, knob with base brown, dorsal rib and 



