94 INSECUTOR INSCITI^ MENSTRUUS 



joint over twice as long as broad ; arista yellowish, blackish on 

 distal half, long-plumose. Mesonotum shining yellow-brown 

 with violaceous reflections and with five indistinct darker longi- 

 tudinal stripes ; pubescence fine, black. Scutellum large and 

 very prominent, convex at base and apically with a deep trans- 

 verse median impression ; color darker than mesonotum and 

 with stronger violaceous luster; a series of rather coarse and 

 dense, but short, black bristles along posterior margin. Pleurae 

 yellow-brown, shining. Abdomen broad, rounded, about as 

 wide as long, shining, brownish yellow at base, beyond deep 

 brown stained with black and with faint violaceous reflections. 

 Legs brownish black, the knees narrowly dull yellow, the tarsi 

 tinged with yellow on basal portions, the hind pair with the 

 first joint deep ocher-yellow and ventrally with cushion of 

 golden pile. Wings hyaline, the costal and subcostal cells 

 dull yellow, a small dark brown spot at tip of first vein ; second 

 vein ending in the costa just beyond tip of first vein. Halteres 

 ivory white. Length : Body about 7 mm., wing 8 mm. 



Female. — Coloration similar to male. Frons about one-sixth 

 the width of the head, deep shining black, yellow at extreme 

 apex, clothed with short fine pale pile along the sides. Wings 

 slightly broader than in the male, the second vein terminating 

 farther beyond tip of first vein. 



Ancon, Canal Zone, Panama, November, 1915, 8 specimens 

 reared by L. H. Dunn from larvae in decaying contents of a 

 calabash. 



Type, Cat. No. 20646, U. S. Nat. Mus. 



This species varies somewhat in coloration, some specimens 

 showing a more yellowish ground color and more distinct 

 thoracic stripes, while others are very dark and show hardly 

 a trace of yellow on the tarsi. The most interesting variation, 

 however, occurs in the wing-venation. In two of the males 

 the second vein terminates in the costa just beyond the tip of 

 the first vein ; in the third male the second vein ends in the 

 first vein distinctly before the latter reaches the costa. This 

 specimen would naturally be referred to the genus Phalacro- 

 myia, yet it is unquestionably conspecific with the other speci- 



