INSECUTOR INSCITIyE MENSTRUUS 105 
base ; the second flagellar segment dull yellov/, the remainder 
of ih<c flageilum 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 coxae and trochanters bright orange, 
concoiorous with the pleura ; femora dull yellow, the apex nar- 
rowly dark brown ; tibios and tarsi black, 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 
wini'-'base ; an interrupted band along the cord ; stigma large, 
subquadrate, brown ; the wing-apex narrowly margined with 
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 i!f 1 absent ; crossvein r inserted on R„ at a distance beyond 
the fork of R^ + .j about equal to one and one-half of r; cell 1st 
Mo 'arge, 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 will 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 al 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, Rr., Ml and Ms grayish hyaline at their middle ; thorax 
yellowish with a grayish blue bloom especially on the pleura and 
coxae, abdomen with blackish Ijands on the anterior margins of 
the segments, the incisures yellowish trifasciata Roder 
'Roder, V. von. Dipteren von der Insel Portorico ; Stett, entomol. 
Zeit., vol. 46, p. 338, 1885. 
