58 THE CANADIAN ENTOMOLOGIST. 



Ocelli, five in each group ; three are arranged in a transverse row 

 immediately behind the antennal sockets, the remaining two are about 

 equidistant from each other, and from the nearest ocellus in the front row. 



Antennse inserted in large sockets at the sides of the front ; the basal 

 articulating segment is membranous, protruding and bears three chitinized 

 joints, the first of which is short and thick, subcylindrical, very sparsely 

 bristled ; the second is longer and more slender, slightly clavate and 

 attenuate towards each end, also sparsely bristled, a heavy seta close 

 to the tip. The third, the terminal, joint is small, subcylindrical, tipped 

 with a long seta and two or three smaller ones. 



Mandibles subtriangular, strongly ridged and toothed ; apex sharp, 

 produced, just inside of the tip is a broad lobe bearing three denticles, 

 while half way between this lobe and the base is a large triangular tooth. 



Maxillse blade-like, apical and inner marginal portion clothed with 

 stout, rather short, thickly placed bristles. Palpi of three short subequal 

 joints. 



Labium small, ligula rounded in front, beset with fine bristles and 

 pits. Palpi short, two-jointed, the basal joint about as broad as long, the 

 apical more slender, narrowed slightly to the tip. 



Prothorax broader than long, dorsal scute with a prominent bristle 

 on each side behind the front angles ; the anterior margin of this scute 

 is nearly straight, the sides are moderately arcuate, the base narrower 

 than the apex. The spiracle is located in the lateral membrane near 

 the hind angles, and is very large and prominent. Prosternal scute 

 broader anteriorly, front margin arcuate, apex rounded. 



Mesothorax much shorter than the prothorax, dorsal scute with a 

 long bristle on each side near the middle of the margin, sides of this 

 scute rounded, not quite covering the dorsal aspect of the segment. 

 Ventral scute less strongly chitinized, subquadrate or roughly pentagonal 

 in outline, quadrisetose. No spiracle. 



Metathorax about like the mesothorax, the scute on the ventral 

 surface slightly differing as shown in the figure. 



Abdomen with nine segments visible from above, anus inferior, pro- 

 jecting. The segments one to eight are similar, each with a broad dorsal 

 scute, the sides membranous and prominent. Each scute bears a row of 

 four short bristles arranged transversely near the hind margin, the mem- 

 branous prominences each bear a long, slender seta. Ventral scutes 

 imperfectly chitinized, each with six oblique longitudinal impressions, and 

 about eleven setse arranged in two rows as shown in the figure. Ninth 



