INSECUTOR INSCIT1.-E MENSTRUUS 105 



base ; the second flagellar segment dull yellow, the remainder 

 of the flagellum sparsely hairy. Frontal tubercle broad and 

 low. Head dark brown with a sparse grayish bloom on the 

 occiput and sides of the vertex. 



Thorax clear light orange without stripes or darkening of 

 any kind. Halteres short, the stem pale yellow, the knob dark 

 brown. Legs with the coxje and trochanters bright orange, 

 concolorous with the pleura ; femora dull yellow, the apex nar- 

 rowly dark brown ; tibiae and tarsi blacl:, the claws yellow. 

 Wings with a light yellow suffusion, the costal cell dark brown : 

 a brown ocellate mark around the base of the radial sector ; 

 a semilunar mark across the basal cells midway between the 

 arculus and the origin of the sector, the concavity toward the 

 wing-base ; an interrupted band along the cord ; stigma large, 

 subquadrate, brown; the wing-apex narrowly margined v,nta 

 brown ; the apical cells of the wings with pale grayish brown 

 clouds in the neighborhood of the crossveins and deflections 

 of veins ; the anal and cubital cells slightly grayish. Venation : 

 Cell Ml absent ; crossveivi r inserted on R„ at a distance beyond 

 the fork of R^ -f 3 about equal to one and one-half of r; cell 1st 

 .Mo large, the basal deflection of Cu^ inserted before the mid- 

 dle of the cell. 



Abdomen bright orange, darkening toward the apex, on seg- 

 ments 8 and 9 shiny black. 



Holotype, male, Mayaguez, Porto Rico, December 4, 1913 

 (R. H. Van Zwaluwenburg). 



Type, Cat. No. 19660, U. S. Nat. Mus. 



The only species with which B. ocellifera v/ill be confused 

 is Briocera trifasciata Roder,' likewise from Porto Rico. The 

 two flies may be separated by means of the following key : 



1. Wings with three bands, the first at the wing-root, the second at the 

 origin of the radial sector extending across the wing and connected 

 with the basal band in the anal cells; wing-apex largely dark, the 

 cells /?3, Rs, Ml and Ms grayish hyaline at their middle; thorax 

 yellowish with a grayish blue bloom especially on the pleura and 

 coxae, abdomen with blackish liands on the anterior margins of 

 the segments, the incisures yellowish trifasciata Roder 



^Roder, V. von. Dipteren von der Insel Portnrico; Stott. entninoi. Zeit.. 

 voL -}6, p. ;i3S, lS8ij. 



