STREPSIPTERA 



547 



Fig. 671. — Opthalmochlus diiryi. (After Pierce.) 



Figure 671 will serve to illustrate the appearance of an adult male 

 stylopid. The more striking features are the flabellate antennae; 

 the large, 

 stalked, com- 

 pound eyes; 

 the shortness 

 of the pro- 

 thorax and 

 the mesotho- 

 rax, and the 

 great length 

 of the meta- 

 thorax; the re- 

 duction of the 

 fore-wings to 

 club-s h a p e d 

 appendages; 

 and the large 

 size of the 

 hind wings. 



The an- 

 tennas of adult 

 males differ 



greatly in form in the different families of this order. The number of 

 antennal segments varies from four to seven ; the third segment is 



always furnished 

 with a lateral pro- 

 longation, a flabel- 

 lum, and one or 

 more of the follow- 

 ing segments may 

 or may not be fla- 

 bellate. 



The compound 

 eyes of adult males 

 are large and more 

 or less stalked. The 

 facets are separated 

 by densely ciliate 

 walls. 

 The mouth-parts are greatly reduced; those of two adult males 

 are represented in Figure 672. The mouth opening is small. The 

 labrum and labium are wanting as distinct parts. In AcroscMsmus 

 bruesi (Fig. 672,0) the mandibles are slender, curved, and scimitar- 

 like; beneath the mandibles are the maxillse; these are two-jointed; 

 the second segment is believed to be the reduced palpus. In Pento- 

 zocera australensis (Fig. 672, b) the mandibles are greatly reduced, 

 but the maxilllary palpi are quite large. 



The three pairs of legs are similar in form. The tarsi are five- 

 jointed in one family (Mengeid^), and furnished with two claws; 



Fig. 672. — Mouth-parts of male stylopids: a, Acros- 

 cMsmus bruesi. (After Pierce.) b, Pentozocera austral- 

 ensis. (After Perkins.) 



