382 



The larval stage of a great majority of the larger Asilidae lasts 

 over two years, and the specimen above described is evidently a first- 

 year larva, as the structure of the maxillae and the form of the body 

 diverge from the normal form for mature larvae. 



Dasylus sp. ? 



Larva. — Length, 24 mm. White, with head, a large portion of 

 dorsum of prothorax, and apex of last segment black. 



Head very broad, the exposed portion, when seen from above, 

 broader than long; maxillae trilobed owing to the presence of 2 dis- 

 tinct notches on the outer margin, the anterior one being very sharp, 

 the posterior one slightly rounded and not so deep; apices of maxillae 

 blunt; maxillary palpi distinctly 2-jointed, basal joint stouter and a 

 little shorter than apical, the latter about twice as long as thick ; man- 

 dibles very short, not extending beyond middle of maxillae; antennae 

 indistinguishable ; surface hairs strong but not very long. Prothorax 

 with a brownish area on dorsum, the surface of which is studded 

 with numerous small black chitinous spots; dorsal surface of thoracic 

 segments finely striated ; prothorax longer than metathorax ; ventral 

 hairs strong. Abdominal segments 1-6 each with an encircling series 

 of pseudopod-like processes on their posterior half ; penultimate, 

 spiracle-bearing, segment distinctly shorter than ultimate ; dorsum of 

 last segment with 4 strong hairs in a curved transverse series just 

 caudad of the depressed segment, and a chitinized plate at tip which 

 •is furnished with 3 short teeth and has a short hair ventrad of each 

 lateral tooth ; ventral surface of apical segment with 2 long hairs 

 about middle and 2 near tip. 



Pupa (PI. LIU, Fig. 8). — Length: male 13 mm.; female, 25 mm. 

 Brownish testaceous, distinctly shining; armature and wings dark 

 brown. 



Upper cephalic thorns strong, gradually tapered from base to 

 apex, separated at apices by more than their own length; lateral 

 cephalic armature consisting of 4 stout thorns ; a short stout thorn 

 on lower anterior eye-margin, and a smaller one on anterior portion 

 of cheek; face as in Figure 1, Plate LIV. Thoracic spiracles very 

 little above the level of thoracic dorsum, the aperture reniform, the 

 area laterad of spiracle distinctly striate and with an irregular de- 

 pression ; thorns at base of middle leg 3 in number, flattened and high- 

 ly polished ; protuberances at base of wing in the form of a sharp 

 thumb-nail-like vertical carina; apices of fore tarsi falling far short 

 of apices of wings; apices of mid tarsi extending to apices of wings 

 in male, slightly beyond them in female ; claws and pulvilli of hind 



