62 INSECUTOR INSCITLt MENSTRUUS 



ished, the disk reddish-yellow, or with indications of three brownish yel- 

 low stripes. Abdomen brown or brown-black. Legs with only the tarsi 

 slightly browned. Wings slightly grayish ; veins brown. 



Frontal triangle slightly rounded on posterior lateraJ margins, where it 

 falls short of reaching the margins of frontal stripe, and distinctly short of 

 reaching anterior margin of frons ; surface hears on frons black, those on 

 lateral margins setulose ; arista with rather distinct pubescence ; proboscis 

 and palpi normal ; cheeks ncirrow, about one-sixth the height of eye, 

 lower half with numerous, distinct hairs ; eyes shortly but distinctly haired. 

 Hairs on mesonotum pale, rather long and numerous, bristles black ; 

 pleurae unmarked ; scutellum paler them mesonotum, convex, outline reg- 

 ularly rounded, disk bare, four marginal bristles present, the apical two 

 very long and widely separated, the basal two very short, and close to 

 the apical pair, sometimes there is also present a small hair on each side 

 anterior to the basal bristle. Abdomen slender, longer than thorax, highly 

 shining, the surface heiirs yellowish. Legs thickly covered with peJe hziirs. 

 Wings narrow ; costa and posterior margin with unusually long marginal 

 hairs ; second costal division about one-third longer than third ; third and 

 fourth veins subparallel ; last section of fifth vein distinctly longer than 

 penultimate section of fourth, and not reaching wing margin ; outer cross 

 vein with its upper extremity distinctly nearer to wing tip than its lower. 

 Halteres yellow, knob pale yellow. 



Length, 1.5 mm. 



Type: Cat. No. 15673, U. S. Nat. Mus. 



Locality : Bayamon, Porto Rico, January, 1 899 (Busck). 



Paratypes : Utuado and Aguadilla, Porto Rico, and Vieques Island, 

 January and February, 1 899 (Busck). Both sexes, 7 specimens. Fe- 

 male similar to the male in color, etc. 



This species has been recorded by Coquillett (Proc. U. S. Nat. Mus., 

 vol. 22, 1900) as Oscinis virgata Coq. While close to that species in 

 some respects it differs in being smaller, in having the mesonotum unstriped, 

 or indistinctly striped, in having the pleurae unspotted, and in the less 

 thickened arista, etc. Confusa is more nearly allied to mitis Williston 

 {Oscinis) than to Coquillett 's species, but mitis has the antennae entirely 

 yellow, and differs in several other respects from confusa. Becker's spe- 

 cies, ruhicunda, comes close to confusa but he gives the third and fourth 

 veins as parallel in his description, while there are other minor differences 

 also present. 



