DJPTERA 



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 : 



Fig. 9QO.— Head of Anopheles. 

 explained in the text. 



(After Nuttall and Shipley.) The lettering is 



the antennse (a) ; the labnmi or labnmi-epipharynx (Ir-e) ; the hypo- 

 pharynx (h) ; the two mandibles 

 (m) ; the two maxilla:^ (mx) ; the 

 labiinn (/) ; and the maxillary 

 palpi (mp). 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 labium 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 

 paraglossae. 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 liinule (Fig. 991, 

 /. I) is a small crescent-shaped 

 sclerite immediately above the 

 antennas, which is characteristic 

 of the second suborder, the 

 Cyclorraoha. In most members of this suborder there is a s^.ture 



Fig 



991. — Head of a fly: A, antennse; 

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

 ule; J.S., frontal suture. 



