COLEOPTERA. 



503 



were supposed, for a time, to be represented by the elytra or wing- 

 covers. See pages 494 and 495, where this unfortunate error is dis- 

 cussed. 



Each sternum or ventral part of each thoracic segment is composed 



FIG. 6n. Ventral aspect of a beetle, Enchroma gigantca : /, 

 head; 2 C , gena of the epicranium; 3, eye; 7, antenna; //. 

 thorax; 14, prothorax; i4 e , proepisternum or episternum of 

 the prothorax; i4 f , proepimeron or epimeron of the prothorax; 

 14'. prosternum; 15, mesothorax; 15', mesoepisternum; 15', 

 mesoepimeron; 15', mesosternum; 16, metathorax; i6 c , meta- 

 episternum; i6 f . metaepimeron; 16', metasternum; 16", ante- 

 coxal piece of the metasternum; iy a , coxa; i;" 1 , trochantin; 

 :7 b , trochanter; 17. femur; i7 J , tibia; 17', tarsus; ij el , tarsal 

 claws; T? 02 , pulvilli; 18, elytron. 



of a single sclerite (Fig. 608 /.) As indicated above, the three sterna 

 are designed as the prosternum, mesosternum, and metasternum, 

 respectively. 



In some beetles the metasternuui is divided into two unequal por- 



