XVI INTRODUCTION. 



thorax is of great importance in classification, according as they 

 reach the middle coxa?, or are cut off from them by the junction 

 of the episterna with the metasternum. The epimera of the meta- 

 thorax are also of importance, being sometimes visible, sometimes 

 covered by the elytra. 



Under surface op TTarpalus catjgtsosfs. 

 a. Ligula; 6. Paraglossia ; c. Supports of labial palpi; d. Labial palpus; e. Mentum ; 

 /. Inner lobe of maxilla; g. Outer lobe of maxilla; h. Maxillary palpus; i. Mandible; 

 k. Buccal opening; I. Gula or throat; m, m. Buccal sutures (ought to be more distinct) ; 

 n. Gular suture; o. Prosternum ; p'. Episternum of prothorax ; p. Epirueron of protho- 

 rax ; q, q', q". Coxae ; r, r, r. Trochanters ; s, s', s''. Femora or thighs ; t, t', t". Tibia ; 

 v, v 2 , v 3 , &c. Ventral abdominal segments; w. Episterna of mesothorax (the epirueron is 

 the very portion immediately behind it, and does not touch q' the middle coxa, better 

 represented on the left side of the figure) ; x. Mesosternum ; y. Episterna of metathorax ; 

 y'. Epirueron of metathorax ; z. Metasternum. 



