DIPTERA 



775 



Figure 990 represents a side view of the head of Anopheles with the 

 bristle-like organs removed from the sheath. The parts are as follows : 



ir-e 



mx 



Fig. 990. — Head of Anopheles. 

 explained in the text. 



(After Nuttall and Shipley.) The lettering is 



the antennas (a) ; the labnmi or labrum-epipharynx (Zr-^) ; the hypo- 

 pharynx (/i) ; the two mandibles 

 (m) ; the two maxillae (mx) ; the 

 labiimi (/) ; and the maxillary 

 palpi i^np). The labium is the 

 sheath in which the six bristle- 

 like organs are normally enclosed ; 

 the maxillary palpi are not en- 

 closed in the sheath. At the tip 

 of the labitun there is on each 

 side a lobe-like appendage ; these 

 are termed the labella. The lab- 

 ella are believed by some writers 

 to be the labial palpi ; but it seems 

 more probable that they are the 

 paraglossse. The labella of certain 

 flies are quite large ; in the house- 

 fly, for example, they are ex- 

 panded into broad plates, which 

 are fitted for rasping. 



The frontal lunule (Fig. 991, 

 /. /) is a small crescent -shaped 

 sclerite immediately above the 

 antennae, which is characteristic 

 of the second suborder, the 

 Cyclorrapha. In most members of this suborder there is a suture 



Fig. 991. — Head of a fly: A, antennas; 

 ar, arista, E, eye; /. /., frontal lun- 

 ule; f.s., frontal suture. 



