412 Annals Entomological Society of America [Vol. V, 
length equal to the width of the wings; 14 segments;! composed of 
spherical nodes joined by clear internodes; first segment cylindrical, the 
second spherical and distinctly larger than any of the other joints, and 
both the first and second segments with numerous fusiform scales as 
well as strong hairs; segments three to twelve inclusive with basal nodes 
and distal slender internodes; nodes with whorls of long white 
hair directed distad and projecting beyond the node of the adjacent 
distal segment; internodes clear, nodes slightly yellow; length of the inter- 
nodes about the same length as the adjacent nodes; segment 13 bilobed,” 
the basal lobe exceeding the other in diameter, separated by a broad 
shallow constriction, coating of hair similar to that of middle segments; 
segment 14 small and inconspicuous, about one-fifth the length of seg- 
ment 13, with a few hairs and usually three or four terminal scales. 
Wings ovate, rather acutely angulated at tip of median vein, thick 
coating of hair on upper surface, moderate coating of hair on under 
surface; average length 2.1 mm., extremes of variation 1.74 to 2.28 mm.; 
average width 0.85 mm., extremes of variation 0.66 to 1.02 mm.; upper 
surface with distinctly mottled appearance, due to the presence of 
alternate patches of white and black erect hair; basal region of wing 
with black patches on or near veins II, IIe, V3, VII2; middle region of 
wing with black patches on or near veins II],, IIe, Il, Vi, Ve, VII; 
distinct tufts of black hair at the distal ends of veins II], IIIs, IfIu, Vi, 
V2, VIIz; all intermediate spaces on surface between black patches occu- 
pied by white hair; rarely a very indistinct black tuft at distal end of 
V,. and VIL; fringe on anterior margin smoky, length about one-fifth 
the width of wing; posterior fringe smoky, length about one-fourth the 
width of wing; distinct tuft of long smoky hairs on costal margin at 
base of wing; hair on ventral surface of wing short, white, and nearly 
prostrate; cubital furcation nearer base of wing than tip. Legs white 
with slight tinge of yellow; extremities of distal segments of the tarsi 
tipped with brown; tibia and femora with scattering long black hairs, 
also some short prostrate black hairs intermingled with the white. 
Abdomen white, thickly clothed with long erect white hairs, originating 
on the posterior margin of each abdominal segment, thus producing a 
series of rings of erect hairs; black and gray hairs scanty. Inferior 
genital appendages of male prominent; length (including basis) 0.64 
mm.; basis strongly developed, broad towards caudal extremity, with 
median conical projection, lateral margins converge towards base; 
inferior appendage expanding gradually towards basis; somewhat sig- 
moid in shape; heavy fringe of long white hair on caudal aspect; ter- 
minal spinule small, clavate. Superior genital appendages well devel- 
oped; two segments; a little over one-third the length of the inferior 
genital appendages, proximal segment a little more strongly developed 
than the distal; with a few short whitish hairs. Intromittant organ 
slender. 
1. Care must be taken in estimating the number of segments in this species 
since the thirteenth is of such a nature that an error can easily be made. The 
antenne should be mounted so that the tip lies exactly in a plane at right angles 
to the objective of the microscope, otherwise the superimposed curved surfaces 
of adjacent parts produce appearances which easily lead to error. 
