SCENOPINIDAE OF THE WORLD 253 



dark bro%vTi; halter stem brown, knob with dorsal rib red-brown, re- 

 mainder white with some bleeding from dorsal rib. Front and middle 

 legs orange-browii, tarsi red-brown; hind leg red-brown, tarsus with 

 first segment orange, remainder red-brown. 



Abdomen second segment black, granular, submetallic; membrane 

 black except for extreme lateral margins white; remaining segments 

 black, submetallic, posterior margins with large white patches on 

 lateral portions of membrane; eighth segment black, sternum broadly 

 excavated with two rounded points midlaterally; see figure for 

 details. 



Male. — Unknown. 



Length: Female body 5.1-6.1 mm., wing 3.2-4 mm. 



Type-locality: Mill Valley, Marin Co., California; 29 July 1948 

 (H. B. Leech). 



Holotype: Female (CAS) 8934. 



Paratypes: 4 99, Mill Valley, California, 20 September 1947, 

 10 :May 1955, 10 June 1957, 10 July 1957 (H. B. Leech) on window in 

 house; 1 9, Mill Valley, September 1948 (E. S. Ross); all (CAS). 



170. Pseudatrichia longiventris, new species 



Figure 164 



Male. — Head red-brown, longer than high; eyes red-brown above, 

 black-brown below, with a very narrow postocular flange; frons 

 elongate, triangular, continuing as a thin band between the eyes to 

 the ocellar tubercle, swollen above antennae, granular below, shining 

 above; ocellar tubercle red-brown, granular; ocelli orange-red; back 

 of head concave in center below ocellar tubercle, swollen laterally, 

 dusted with gray pollen; antenna red-brown, first and second seg- 

 ments short, third segment oval, short. 



Thorax dorsum black-brown, granular vnih a pollinose patch above 

 humeral callus; humeral and supra-alar calli red-brown, scutellum 

 dark red-brown; pleurum red-brown, shining. Wings brown, smoky; 

 veins brown, halter stem red-brown, knob red-brown. Foreleg with 

 femur red-brown, tibia and tarsus yellow-brown; middle leg with 

 femur red-brown, tibia light red-brown, tarsus yellow-brown; hind 

 leg with femur and tibia red-brown, tarsus yellow-brown. 



Abdomen segments 2-4 dark red-brown, pebbly, with blue and 

 green metallic glints under light; remainder red-brown, subshining 

 without glints; segments 2 and 3 with white posterior membranes, 

 remainder with orange-brown posterior membranes, segment 7 

 sharply constricted near base; see figure. Ninth segment withdrawn 

 into seventh; for details see figure. Differs from Pseudatrichia 

 punctulata in the shape of the ninth tergum and aedeagal parameres. 



