HEMIPTERA. 269 



ence ; and Nepa has only one, of which but few 

 ither instances are afforded by the class. 



The general forms and relative position of the parts 

 lescribed, will be well understood from an inspection 

 f Plate XVIII. which represents the details of a 

 haracteristic example of each of the two great divi- 

 ions of this order. 



Fig. 6 is a highly magnified view of an insect belonging to 



he heteropterous section, Pentatoma rafipes 9 a common Brit- 



sh species. The wings on one side are expanded, the others 



fi situ. For greater perspicuity, the various segments, where 



overed by superincumbent organs, are represented by dots. 



T, the head , o, a, the eyes ; b, the ocelli ; c, one of the an- 



ennae ; T 1, upperside of the prothorax ; I' one of the pro- 



horacic legs ; T 2, upperside of the mesothorax ; S c, scutel- 



im greatly developed and extending over the metathorax 



nd part of the abdomen v ^ one of the hemelytra ; fa, 



e leathery basal portion of the hemelytra ; hm, the mein- 



ranous or apical portion ; Tone of the mesothoracic legs ; T 3, 



per side of the metathorax, greatly reduced in size, sup- 



rting the wings (one of which is extended, W 2 ), and the 



etathoracic or third pair of legs I'" A, abdomen. Fig. 7. 



ic head and prothorax of the same insect seen from beneath ; 



the eye ; c, base of antennae ; Ir 9 labrum or upper-lip, long, 



d transversely striated ; /&, the ftmr-jointed lower-lip trans- 



rmed into an elongated canal for the reception of four slender 



tse, gg, kh, which represent the mandibles and maxillae , 



raised portion of the underside of the head, forming a gutter, 



which the base of the labrum rests ; T 1, underside of the 



othorax ; I' base of one of the prothoracic legs ; Z, the cavity 



the prothorax, into which the anterior narrowed part of the 



esothorax (marked in fig. 6 by the letter z) is received. 



ig. 8. Side view of the head, the respective parts lettered as in 



;. 7 Fig. 9. One of the anterior tarsi of Pentatoma rufipes, 



ewing the emargination at the base of the tibia, and the pul- 



Ui attached to the base of the claws. 



