338 PROCEEDINGS OF THE NATIONAL MUSEUM vol. io9 



ments III, XI-XV. Palpal segments in proportion of 7:14:20:7:9, 

 third segment short and swollen, 1.6 (1.4-1.8, n = 9) times as long as 

 greatest breadth, with a very deep, large sensory pit opening by a very 

 small distal pore. Mandible with 10 (10-11, n = 3) very small, almost 

 vestigial teeth. 



Thorax. — Mesonotum yellowish brown with a prominent pattern of 

 narrow, darker brown bands as figured, principall}^ a very narrow 

 median longitudinal line extending from anterior margin to scutellum 

 and a transverse band across sutural level with short, broader, anterior 

 and posterior, lateral longitudinal extensions. Scutellum yellowish, 

 narrowl}^ dark brown in middle and on extreme ends; postscutellum 

 brownish; pleuron yellowish, dark brown transversely across middle. 

 Legs brownish, all femora with subapical, all tibiae with subbasal 

 and hind tibia with apical narrow pale rings; hind tibial comb with 

 four (n = 12) spines, the one nearest the spur longest. 



Wing. — Pattern as figured, pale spot over r-m crossvein very small 

 but extending in full width to costal margin; poststigmatic pale spot 

 in cell Ks double, the posterior part lying behind second radial cell; 

 distal pale spot in cell R5 transverse, not reaching anterior wing margin; 

 veins Mi and M2 each with a narrow, elongate pale spot lying next to 

 anterior side next to base of vein, the two at nearly the same longi- 

 tudinal level, the pale spot lying next to vein M2, in Panama and 

 Guatemala material only, rarely may be extended caudad to straddle 

 the cell (typical form), usually lying entirely in front of cell (? variety 

 cacozelus) ; pale spots in apices of cells Mi and M2 far removed from 

 wing margin; apices of veins Mi, M2 and M3+4 each with a pale spot at 

 wing margin; pale spot in cell M4 with broadened extension bordering 

 posterior margin of vein M3+4; three pale spots in anal cell, one at 

 base and two in distal portion; small pale spots present lying behind 

 medial fork and in front of mediocubital fork. Macrotrichia numerous 

 but not dense, extending to base of cell M2 and over distal half of 

 anal cell; costa extending to 0.61 (0.59-0.62, n = 12) of distance to 

 wing tip. Halter pale. 



Abdomen. — Dark brown, proximal terga pale grayish. Sper- 

 mathecae two, slightly pyriform, subequal, each measuring 0.043 by 

 0.034 mm., the bases of the ducts not sclerotized. 



Male genitalia. — Ninth sternum without caudomedian excava- 

 tion; ninth tergum short and tapered with distinct caudomedian notch 

 and very slender apicolateral processes. Basistyle with ventral root 

 very slender, pointed, dorsal root stouter; dististyle slender with 

 hooked, pointed tip. Aedeagus with basal arch rounded, extending to 

 about a third of total length of aedeagus; posterior portion tapered 

 to a relatively stout, truncated tip. Parameres each with large, iat- 



