194 THE CANADIAN ENTOMOLOGIST, 



The antennee are as long as the head, and four-jointed ; the first or 

 basal joint is short and stout ; the second is cylindrical, or but slightly 

 narrowed at the upper end, nearly straight, and as long as the width of 

 the labium, or a little more than half the length of the whole antennae ; 

 there are a number of long hairs or bristles on the outer side of the distal 

 half of this joint ; the third is more slender, slightly more than half the 

 length of the second (Fig. 5, a) ; the fourth joint is represented by two 

 very short articles inserted in the third, so that they resemble a pair of 

 minute forceps ; the larger of the two has a cuspidate apex (Fig. 6). 



The labniin is broad, the anterior margin straight, or slightly rounded, 

 the outer corners convex ; the outer third bears a row of rather coarse 

 spines, the two extreme ones being much stouter. The labrum extends 

 beyond and bends down over the mandibles. Its concave under surface 

 is beset with many stiff hairs, some of which extend beyond the margin, 

 forming a fringe. In the front, near the middle of this concave surface, 

 there are eight protuberances ; four smaller ones in a group ; outside of 

 these, two on either side,' are situated the remaining larger ones. These 

 are tooth-like (Fig. \2, a and b). Beginning back as far as the middle of 

 the mandibles is a corneous strip, which soon divides, the branches extend- 

 ing to the outer angles of the labrum (Fig. 12). 



The Diandibles are large, brown or black towards the tips. Seen 

 from above the outline is triangular ; in the younger larvte these organs 

 are relatively shorter, making the outline more nearly that of an equilateral 

 triangle. The basal edge is slightly convex, and bears just beyond the 

 middle the ball for the articulation of the organ with the elbowed corneous 

 support of the cheeks. (In some examples the ball appears to be situated 

 nearer the outer angle than in others). At the inner angle there is a pro- 

 cess and a chitinous piece, apparently articulated with it, to which the 

 tendon of the flexor muscle is attached ; the outer angle is somewhat re- 

 entrant ; the termination of the extensor muscle appears to be quite similar 

 to that of the flexor ; the outer edge is nearly straight, bending inwards a 

 little towards the apex ; the inner line is straight to near the middle where 

 it bends in the blade, becoming spoon shaped j the biting edge is evenly 

 rounded. When the organ lies with the inner face uppermost, it is seen 

 that in the basal part there are two laminte not united with each other on 

 their front and posterior edges ; at the lower part of the concave part of 

 the blade arise two tufts of hair, the outer one is short and bristle like, 

 the other is long, reaching back and nearly across the throat (Fig. 8). 



