25 



front of it, and a median line on under side, the borders of the scutellum 

 and median line of the abdomen all black; median line of the head and 

 eight transverse bands on dorsum of abdomen dusky. Wings cinere- 

 ous, the costal space fuliginous, the veins blackish ; a streak near the 

 discoidal vein in front and a narrow oblique streak behind the vein 

 colorless. There appears to be several branches to the discoidal vein, 

 which however gradually disappear in the mounted specimens. Sur- 

 face of the wings irregularly reticulated. Posterior wings present, 

 though small, and broadly §-shaped, bearing four stout hooks at the 

 apex. 



Antennae ten-jointed, reaching to the middle of the abdomen. Joint 

 three is longest and somewhat stouter at the apex; the joints following 



Fig. 8.—Xylococcus betulce: a, antenna of male, second stage; b, male larva, fourth stage; c, antenna of 

 male, fourth stage; d, pupa skin: e, male imago, dorsal view; /.male, side view; g, end of body of 

 male, with sexual organ ; h, hind-wing of male— all much enlarged (original). 



are cylindrical and diminish gradually in length; the first joint is 

 stoutest and shortest, the second joint somewhat longer; all are pro- 

 vided with rather long and fine, irregularly arranged hairs. Eyes 

 large, projecting, and quite coarsely facetted. Legs long and quite 

 stout; the tibia? hairy; tarsi two-jointed, the first joint minute, though 

 distinct; digitules extremely fine. Style short, stout, conical. The 

 sexual organ is at least as long as the abdomen, stout, and densely 

 covered with forward-directed, lanceolate scales. The insect is cov- 

 ered above with a short and wool-like excretion, while the sixth and 

 seventh abdominal segments bear each a dense, transverse, dorsal 

 brush of delicate, white, and hair-like threads, exceeding the abdomen 



