BITING MIDGES — WIRTH AND BLANTON 383 



isolating a small round black spot behind apex of second radial cell; 

 distal pale spot in cell R5 quadrate, broadly extending across cell from 

 anterior wing margin to vein Mj; two pale spots present in cell Mj, the 

 proximal one merged into transverse band of wing, the distal one 

 failing by less than its length to meet wing margin; two pale spots in 

 distal part of cell M2, the distal one meeting wing margin; pale spot 

 in cell M4 large and broadly meeting wing margin; two pale spots in 

 distal portion of anal cell; cell M2 with small pale spot in front of 

 mediocubital fork and a pale spot behind medial fork; base of wing 

 broadly pale. Macro trichia numerous on distal half of wing, a few in 

 cell M4 and anal cell; costa extending to 0.63 (0.60-0.66, n = 12) of 

 distance to wing tip. Halter yellowish. 



Abdomen. — Dark brown; cerci pale. Spermathecae two, pyri- 

 form, slightly unequal, measuring 0.055 by 0.038 mm. and 0.050 by 

 0.036 mm., the bases of the ducts sclerotized a considerable distance. 



Male genitalia: Ninth sternum with a moderately deep caudo- 

 median excavation, the ventral membrane spiculate; ninth tergum 

 long and tapering, the apicolateral processes long and pointed. Basi- 

 style with ventral root foot-shaped, dorsal root slender; dististyle long 

 and slender, moderately curved. Aedeagus with rounded basal arch 

 extending to about half of total length, the basal arms curved and 

 slender, the distal apex slender and rounded with fine distal spinules. 

 Parameres each with large basal knob, stem gently curved on basal 

 portion, slender, distally slightly sinuate, without ventral lobe, very 

 long, with pointed tip bearing a lateral fringe of fine spines. 



Distribution: Brazil; Panama; Trinidad (Tucker Valley). 



Panama records. 



Canal Zone: Camp Pifia, Fort Davis, Fort San Lorenzo, Fort Sherman, Loma 



Boracho, Madden Dam, Mojinga Swamp. 

 Col6n Province: Nuevo Chagres, Pifia. 

 Dari:6n Province: El Real, Jaque, Punta Patino. 

 PanamX Province: La Jolla, Pacora, Pedregal, Rfo Trinidad (Biisck, coll.), 



Tocumen. 

 Veraguas Province: Rio Santa Maria. 



Discussion: Barbosa described pavcienfuscatus from two cotype 

 specimens in the U. S. National Museum: a pinned female from 

 Manaus, Amazonas, Brazil, June 1931, R. C. Shannon, which we are 

 here designating the lectotype, and a female (paratype), mounted on 

 a slide, from Rio Trinidad, Panama, June 9, 1912, A. Busck. 



This species, while remaining remarkably constant in color and wing 

 pattern characters and male genitalic structure, exhibits an interesting 

 type of variation in structural characters which we suspect may lead 

 to the recognition of subspecies when more distributional records are 

 obtained. For example, the Panama specimens from near the Canal 

 Zone have a much stouter third palpal segment (1.64-2.09 times as 



