388 PROCEEDINGS OF THE NATIONAL MUSEUM vol. io9 



anterior wing margin; cell Mi with two elongate pale spots, the distal 

 one attaining distal wing margin; large pale spots present in ends of 

 cells Ma and M4, pale areas in cell M2 at base, one lying behind medial 

 fork, one lying in front of mediocubital fork and another between the 

 latter two and the pale spot at apex of cell M2, all the proximal spots in 

 cell M2 narrowly connected by a pale line running through the axis of 

 cell; two pale spots in distal portion of anal cell more or less coalesced. 

 Macrotrichia sparse over distal half of wing and in anal cell; costa 

 extending to 0.65 (0.63-0.67, n=10) of distance to wing tip. Halter 

 pale. 



Abdomen. — Dark brown. Spermathecae two, pyriform, slightly 

 unequal, measuring 0.070 by 0.050 mm. and 0.062 by 0.042 mm., the 

 bases of the ducts sclerotized a short distance. 



Male genitalia: Ninth sternum with very shallow caudomedian 

 excavation; ninth tergum long and tapered, apicolateral processes 

 long and closely approximated. Basistyle with ventral root broad 

 and foot-shaped, with distinct heel and flat sole, dorsal root short 

 and slender; dististyle long and slender, apex slightly curved. Ae- 

 deagus with short, broad, pointed basal arch, the basal arms rather 

 stout, median portion long and slender with a deeply bifid (2-pronged) 

 apex. Parameres each with knobbed base, stem stout and nearly 

 straight with a subapical ventral lobe, distal portion greatly narrowed 

 to a curved, flattened, distally pointed blade with about five 

 lateral barbs. 



Distribution: Panama; Honduras; Mexico; Nicaragua. 



Panama Records: 



BocAS DEL ToRo PROVINCE: Almirante. 



Canal Zone: Atlantic side; Fort Clayton, Fort Davis, Fort Gulick; Fort Sherman, 



France Field, Huile Sia Clara(?), Loma Boracho (type locality), Madden 



Dam, Mindi Dairy, Mojinga Swamp, Tabernilla. 

 CHiRiQuf Province: Concepci6n, David, Tortugas. 

 Col6n Province: Cativd, Pifia. 

 DARi:fiN Province: El Real, Garachin^, Jaqu6. 

 PanamX Province: Arraijdn, Capitana, La JoUa, Pedregal, Isla Taboga, Tocu- 



men. 

 Veraguas Province: Rio Santa Maria, Las Palmas. 



Discussion: Two species from Venezuela, discrepans Ortiz and 

 Mirsa and avilaensis Ortiz and Mirsa, are closely related to dicrourus. 

 The former species is larger (wing 1.9 mm. long), wing with the pale 

 spot at the end of the costa entire, not broken into two more or less 

 separate spots and the lower portion not bending around U-shaped 

 proximad toward vein R4+5 and not isolating a separate black spot 

 behind end of second radial cell, the three discal pale spots in 

 cell M are discrete and not connected by a long pale line, there are 



