1921] NATURAL SCIENCES OF PHILADELPHIA. 53 



very long and slender, much longer than the segments that bear 

 them; between the bases of the pectinations a small hairy tubercle; 

 the first flagellar segment apparently bears pectinations but this is 

 uncertain, as this part of the organ is badly injured by pests; scapal 

 segments dark brown, flagellar segments with the basal swelling 

 and pectinations dark l:)rown, the elongate terminal pedicel of each 

 segment conspicuously ivory-white to produce a bicolorous appear- 

 ance. Head dark grayish brown, the eyes practically contiguous 

 on the vertex. IVIesonotal praescutum dull reddish brown with a 

 broad darker brown median stripe and very indistinct and abbrevi- 

 ated lateral stripes; remainder of the mesonotum dark brownish 

 testaceous. Pleura dark brown, sparsely pruinose; sternites beneath 

 obscure yellow. Halteres light yellow, the knobs broken. Legs 

 with the coxae dark brown on the basal half of the outer face, the 

 apical half suddenly pale yellow; trochanters yellow; femora brown, 

 paler basally, the tips broadly and indistinctly paler and including 

 a narrow brown subterminal ring; tibiae and tarsi dark brown. 

 Wings with a strong brownish gray tinge, sparsely variegated with 

 dark brown and subhyaline ; cell Sc yellowish ; the dark brown areas 

 appear as clouds at the origin of Rs, tip of Sc, along the cord, outer 

 end of cell 1st M2 and at the stigma; wing-apex darkened; the sub- 

 hyaline areas occupy the radial cells before the origin of Rs, most 

 of cell 1st Ri, cell 2nd Ri beyond the stigma; in cell Rs one before and 

 one beyond the level of r; veins dark brown. Venation: Sc long, 

 Sci extending to about opposite two-thirds the long Rs, Sco near 

 the extreme tip of Sci; Rs long, strongly arcuated at origin; r at 

 the tip of /?,; r-m about one-half the basal deflection of M, + i; cell 

 1st Mi long and narrow, rectangular, about equal to vein Ms beyond 

 it; basal deflection of Cui just beyond the fork of M. Abdomen 

 reddish brown, the apical two-fifths of each segment dark brown. 

 Male hypopygium very large and comphcated in structure; pleurites 

 small, about as large as the ventral pleural appendages, the proximal 

 face produced inward into a cylindrical dark brown arm that is 

 fringed with bristles along the cephalic face; the caudal face bears 

 near midlength a tubercle tipped with two long bristles. Ventral 

 pleural appendage fleshy, the proximal face produced inward as a 

 yellow, slightly curved arm that bears two slender spines beyond 

 midlength on the caudal face, these spines with the tips squarely 

 truncated. Dorsal pleural appendage a long,- cylindrical, slightly 

 curved arm with the tip suddenly narrowed and acute. Gona- 

 pophyses flattened pale blades, the pfoximal angles produced caudad 

 into narrow knife-like blades that are blackened at their tips. What 

 appears to be the anal tube is very large, blackened, narrow basally, 

 expanded into a conical structure apically, the margin crenulated. 



Habitat. — Peru. 



Holotype, cf , Ym-imaguas, April 1, 1920 (H. S. Parish). 

 Rhipidia perarmata is related to R. calverti Alexander (Costa 

 Rica) and R. bipectinata Williston (Lesser Antilles) but differs strik- 



