1928 ] New Genus and Species of South American Masarids 193 
depressed; the marginal carina broadly and evenly rounded, not 
forming an angle. Inner orbits about one and one-third times 
as far apart on the vertex as at the clypeus. Front hardly 
swollen, with a slight longitudinal median groove over its upper 
two-thirds, beginning at the anterior ocellus. Ocelli large, in a 
flattened triangle; the posterior pair a little nearer to each other 
than to the inner orbits, about twice as far apart as they are 
from the anterior ocellus and about equally distant from the oc- 
cipital margin as from the inner orbits: Interocellar area flat. 
Vertex not swollen, without fovea. Antennae about five times 
as far apart as they are from the inner orbits; the area between 
them flat, without ridge, carina or depression. Clypeus irregular- 
ly hexagonal, with longer upper and lower margins, but little 
wider than long, very slightly convex in the middle, flattened 
toward the base, moderately depressed on the sides in its apical 
third, but without lateral grooves; the anterior, free portion a 
little longer than the basal, interocular part; the upper margin 
straight; the lateral margins forming rounded angles which are 
far removed from the inner orbits; the truncate apex about 
three-quarters of the maximum width of the clypeus, margined 
by a narrow, thickened rim, with a slight inward curve, forming- 
right angles with the lateral margins; the lateral angles blunt, 
flat; owing to the sides of the clypeus being depressed at the 
apex, the apical margin appears triangularly emarginate when 
the head is seen from below. Antenna short, of twelve segments; 
the flagellum much swollen, gradually incrassate from the base 
to about the middle; scape almost uniformly swollen throughout, 
nearly half the length of the flagellum; second segment small; 
third segment about twice as long as the second, about one and 
one-third times as long as wide at the apex; the fourth a little 
over half the length of the third, wider than long; the fifth to 
eleventh much wider than long; the twelfth about as long as 
wide, bluntly rounded at apex; all the segments perfectly normal. 
Mandibles of the knife-like type, somewhat decussate, much 
shorter than the length of the eye, stout and but little curved; 
the apex forming a blunt, broadly rounded tooth; the inner 
margin with two shallow notches separating low, blunt teeth; 
the notches being the ends of two deep grooves which run over 
