ARTHROPODA 



ID/ 



butterflies. The masticatory type, which is the more 

 complete, and of 

 which the other is ~ 



but a modification, 

 consists of four 

 horny jaws (mandi- 

 bles and maxilla) 

 and an upper and 

 an under lip (lab mm 

 and labium). Sensi- 

 tive palpi (maxillary 

 and labial} are de- 

 veloped from the 

 lower jaw and lower 

 lip. The labium is 

 also prolonged into 

 a ligula, or tongue 

 (Figs. 219,220,221). 

 The legs are in- 

 variably six in the 

 adult, the fore legs 

 directed forward 

 and the hinder pairs 

 backward. Each 

 consists of a hip, 

 thigh, shank, and 

 foot. 21 Some larvae 

 have also " false 

 legs," without joints, 

 on the abdomen, 

 upon which they 

 chiefly rely in loco- 

 motion (Fig. 73). 

 The wings are ex- 



Under surface of a Beetle (Harpalus caligi- 

 nosus)'. a, ligula; b, paraglossae; c, supports of 

 labial palpi; d, labial palpus; e f mentum;/", inner 

 lobe of maxilla; .g, outer lobe; h, maxillary palpus; 

 /, mandible; k, buccal opening; /, gula, or throat; 

 MI, buccal sutures; , gular suture; o, prosternum; 

 /, episternum of prothorax; /', epimeron; q, g' , g", 

 coxae; r, r, r, trochanters; s, s' , s", femora, or 

 thighs; t, t,' t", tibiae; v, ventral abdominal seg- 

 ments; w, episterna of mesothorax; x, mesoster- 

 num; y, episterna of metathorax; y', epimeron; z, 

 metasternum. 



pansions of the crust, stretched over a network of horny 



