36 



labrum is a large fleshy projection bearing on its ectal surface six pairs 

 of very long setae which extend beyond the lateral margin of the body, 

 and on the ental surface two groups of much shorter setae, which 

 project slightly beyond its caudal margin. All of the appendages of 

 the head are free. The labial palpi are rather short, with three seg- 

 ments, and are somewhat enlarged and blunt at the distal end. The 

 mandibles are exceedingly large and are attached to the ental surface 

 of the clypeus, extending beyond the lateral margin of the body. They 

 are heavily chitinized and serrate along the cephalo-lateral margin. 

 The distal end is broadened and thickened, somewhat circular in out- 

 line, concave and strongly toothed. The maxillae are short and the 

 halves are widely separated. Each half is strongly bent near the dis- 

 tal end, which is directed cephalad and mesad. The maxillary palpi 

 are long, apparently with six segments, and pass from the mouth 

 dorsad and then out towards the lateral margin of the head, making 

 a series of curves which finally bring them between the eyes and the 

 antennae. The distal end is folded close to the body and lies just 

 caudad of the eye. The antennae show a long pedicel with many 

 shorter segments and extend for more than half the length of the 

 wings. 



The thoracic segments are all more or less movable. The thorax 

 is short, strongly elevated, and moves freely, the greater part of its 

 exposed portion being conjunctiva. The mesothorax and metathorax 

 are nearly equal in length, but seem to possess little power of inde- 

 pendent motion. On the dorso-meson of these two thoracic segments 

 and the first abdominal segment is found a strap-like cuticular thick- 

 ening which is apparently for strengthening the thorax. The tegulae 

 are indicated by the dotted lines in Figure 2 because they do not seem 

 to be distinct pupal structures. The thoracic appendages are also free. 

 All of the coxae are visible and usually the femora of the prothoracic 

 and mesothoracic legs. The metathoracic legs are usually hidden be- 

 neath the wings except at the distal end, which normally curves around 

 the caudal end of the body. The wings never extend to the caudal 

 margin of the body. 



The first seven abdominal segments are movable in both sexes. 

 The remaining segments are not distinctly sutured and possess no 

 power of independent movement. The genital openings are rather 

 difficult to locate. That of the male is found as a slit-like opening 

 on the ventro-meson of the ninth segment (Fig. 4). There are two 

 openings in the female (Fig. 7, go), apparently located on the ventro- 

 meson of the eighth and ninth abdominal segments. 



